Monster Cookies
Truly the best monster cookie recipe! These peanut butter, oatmeal and chocolate chip cookies are so delicious. They're gluten free, too!
Updated by Kathryne Taylor on September 19, 2024
“What are monster cookies, though?” I asked recently, with vague recollections of cookies with M&M’s in them.
“Peanut butter, chocolate, and oat cookies.”
“Well, I’m sold.”
This monster cookie recipe took me about eight tries (nine?) to get right, but they are just right.
I almost gave up on them, to tell you the truth. My fella took a batch to work and overheard his coworker say, “This is the best cookie I’ve ever had,” so I knew I was close.
Here they are, in time for a fun weekend baking project or holiday treat. Let’s make some cookies!
These monster cookies are made with more wholesome ingredients than most. They have a classic bakery look and taste, and the sugar content that goes along with that. (If you’re looking for lightened-up, lower-sugar cookies, check these out, or just make half-sized cookies.)
These cookies are essentially made with peanut butter, eggs, coconut sugar or brown sugar, melted coconut oil or butter, and chocolate. They’re flourless and gluten free, as long as your oats are certified gluten free. I like to think that the nut butter and oats make them a little more redeeming.
How to Make Monster Cookies
These cookies are seriously easy to make with basic ingredients. You don’t even need to remember to soften your butter! Here’s the rundown:
- Combine your peanut butter, sugar and melted oil or butter in a large mixing bowl, and mix well. You could do this in a stand mixer, but I hate lugging mine out. I use my beloved hand mixer (affiliate link). You can also mix these cookies with a big spoon by hand, which will take some muscle but it’s totally doable.
- Add eggs, baking soda and vanilla. Mix again. This is so easy, you might as well turn on some music and dance around while you’re working on these.
- Add your oats and chocolate. Mix again. La lalalala.
- Scoop the dough onto a parchment paper-lined baking sheet. These are big cookies that expand while baking, so I can fit six per half-sheet pan.
- Bake for 10 to 12 minutes, until they’re just starting to turn golden on the edges, then let them cool while you put the next batch in the oven. Repeat one more time and you’re done. (If you’re in a hurry, I think you could bake two sets of six cookies at the same time, with racks in the upper and bottom thirds of the oven.)
Monster Cookie Ingredient Considerations
Quick-cooking oats vs. old-fashioned oats
Quick oats disappear more into the cookies, whereas old-fashioned oats offer a more hearty and discernible texture. Did you know that quick-cooking and old-fashioned oats have nearly identical nutrition properties? Quick-cooking oats are just cut up a little more.
Coconut oil (and other oils) vs. butter
I love using unrefined (virgin) coconut oil in this recipe because it lends a very subtle layer of complexity. I can’t really pick out the coconut flavor, but the cookies taste a little more interesting. You could use a mild extra-virgin olive oil (like California Olive Ranch Everyday) or neutral oil, such as sunflower seed oil, but those tend to be more refined.
Butter works great, too, if you’re going for a super classic monster cookie.
Coconut sugar vs. brown sugar
I like to use coconut sugar since it’s a less refined, more natural sweetener made from evaporated coconut nectar. It doesn’t taste like coconut; it’s similar to brown sugar in flavor. It has been gaining popularity over the past few years. I buy it at Trader Joe’s or Whole Foods.
Brown sugar works, too, and costs less. You might be wondering why the recipe calls for 2 1/2 cups coconut sugar or 2 cups brown sugar—they actually are about the same by weight. Coconut sugar just weighs less per cup.
Chocolate chips vs. chocolate-coated candies
Most monster cookies are made with an equal mix of chocolate chips and chocolate-coated candies (think M&M’s). The candies are fun because you can buy colors that match the seasons or holidays (red and pink for Valentine’s Day, pastels for Easter, red and green for Christmas, multi-colored for Halloween, etc.). I bought my naturally colored candies at Whole Foods, near the bulk bins.
However, I also love these cookies with all chocolate chips. I buy bittersweet chocolate chips, so they satisfy my craving for dark chocolate that way.
Watch How to Make Monster Cookies
Change It Up
Mix up your mix-ins.
Like I said, I love these cookies with all chocolate chips (no candy-coated chocolate). You could even substitute some chopped nuts, raisins or other dried fruit for some or all of the chocolate.
Substitute other nut butters.
I can’t get enough of the peanut butter version, but you could substitute almond butter or sunflower seed butter.
Make smaller cookies.
This recipe yields 18 large cookies, which use 1/4 cup dough each. You could easily make 36 smaller cookies by using scoops of 2 tablespoons each. You cookies will bake up faster, somewhere between 6 to 9 minutes. They’re done when they’re just starting to turn golden around the edges.
Craving more peanut butter and chocolate cookies and desserts?
- Coffee Chocolate Chip Blondies
- Mini Peanut Butter Cups and Chocolate Peppermint Cups
- Chocolate Peanut Butter Crispy Bars
- Peanut Butter Oat Cookies
- Vegan Chocolate Chip Cookies
Please let me know how your cookies turn out in the comments! They’re a real treat and I hope they become your new favorite cookie recipe.
Monster Cookies
Truly the best monster cookie recipe! These peanut butter, oatmeal and chocolate chip cookies are perfectly crisp on the outside and tender on the inside. Recipe yields 18 cookies.
Ingredients
- 1 ½ cups creamy or chunky peanut butter (that’s one full 16-ounce jar minus ¼ cup)
- 2 ½ cups packed coconut sugar or 2 cups lightly packed brown sugar
- ⅓ cup melted coconut oil or 5 tablespoons melted butter
- 3 large eggs
- 2 teaspoons baking soda
- 2 teaspoons vanilla extract
- 2 ½ cups quick-cooking oats or old-fashioned oats (certified gluten-free if necessary)
- ¾ cup bittersweet chocolate chips
- ¾ cup candy-coated chocolates (like M&M’s) or additional chocolate chips
- Optional: flaky sea salt, for sprinkling
Instructions
- Preheat the oven to 350 degrees Fahrenheit. Line tw0 large, rimmed baking sheets with parchment paper or silicone mats for easy clean-up.
- In a large mixing bowl, combine the peanut butter with the sugar and coconut oil. Use an electric mixer or a large spoon to mix until well combined. Add the eggs, baking soda and vanilla, and mix well. Add the oats and chocolate chips and mix until they’re evenly incorporated.
- Working with an ice cream scoop or ¼ cup measuring cup, drop the cookies onto the prepared baking sheets. These cookies spread while baking, so leave several inches around each (I can bake six at a time). If they are irregularly shaped at the base, gently shape them into a more rounded mound. If you’d like your cookies to look extra pretty, dot a few extra M&M’s and chocolate chips on each mound of dough before baking.
- Bake 10 to 12 minutes, until they’re just starting to turn golden around the edges. Do not overbake. Let the cookies cool for 10 minutes before transferring to a cooling rack. In the meantime, bake your next six cookies, and so on.
- If desired, sprinkle the cookies lightly with flaky sea salt. Let them cool completely before storing them in an airtight container. Cookies will keep well for several days at room temperature.
Notes
Recipe adapted from Recipe Girl.
Nutrition
The information shown is an estimate provided by an online nutrition calculator. It should not be considered a substitute for a professional nutritionist’s advice. See our full nutrition disclosure here.
I can’t stop eating these! Seriously delicious!
I love it! Thanks for the feedback, Jaimi.
These were a hit with a very diverse group of folks! They were really easy to make and made a TON of cookies. I ended up refrigerating the dough for a day to finish baking the cookies later and those turned out just like the first batches.
I love it, Ann! Thanks for letting me know the dough works well once refrigerated.
I’m currently making these and I decided to half the recipe. Mine looks NOTHING like yours. In fact, they are so crumbly they barely stick together unless I form them into a ball with my hands. What could I have done wrong?
It could be the ratio as you don’t have enough to get mixed in well, if you followed everything else exactly.
Best cookies I have ever made! So yummy and chewy! I froze half of the batter. I took it out of the freezer today and baked what was left. There are three left, and I have already been asked to bake another batch. Thanks for sharing this recipe!
You’re welcome, Lea!
YES PLEASE!
Give me all the cookies :P These look so so perfect and am I correct to say that these are crisp on the outside and soft and chewy on the inside? Because if that’s the case, that makes them even more desirable – I love me some good crunch. Keep the recipes coming Kate. You’re such an inspiration <3
Thanks, Pia!
Hi – I am a huge fan of your blog, and we eat one of your recipes almost every day. However, is there anything missing from the list of ingredients for these monster cookies? I made them on the weekend and the mixture was so runny, there was no way to roll into balls for cooking. I ended up adding around 2 cups of wholemeal flour to get them the right consistency to roll, and they still ended up very soft.
Despite this, the flavor is great and my kids loved all the choc chips!
Thanks for the fab blog and recipes (I also have your cookbook).
Annabel (Australia)
I’m sorry these didn’t work for you! Hmm.. There isn’t anything missing from the list. Did you use coconut oil or butter?
Such a delicious and versatile cookie recipe! I added shredded coconut along with the chocolate chips and M&M’s. Everyone loved them and I’m so glad they’re gluten free. Your recipes are amazing Kate!
Thanks for sharing, Tara!
These cookies are A-mazing !!! I actually used half candy coated chocolate and half white chocolate chips. Turned out great! Am going to add some nuts next time… yummy. FYI… the longer they cool the better.
Sounds like a great combination, Susan! Thanks for the review.
Made these last night and they came out well. Followed the recipe exactly. My kids love the m & m’s and I love the rolled oats. Only thing is I found these cookies to be a bit too sweet for me. So perhaps consider reducing the sugar – maybe 1.5 cups of brown instead of 2 cups – and consider adding a 1/4 to 1/2 tsp salt to the recipe. Other than that, they are very good. The vegan chocolate chip cookie recipe continues to be my favorite, though. Thanks for all the great recipes!
Thanks for trying this recipe, Jess! The vegan cookies are hard to beat, that’s for sure!
Kate these are fabulous monster cookies! Better than the bakery even! Made a couple additions…raisins, walnuts and to the last batch added a half grated carrot….they are great…won’t last long in my house….love all your recipes and look forward to your emails. Thank you thank you!! ❤️Anita
Better than bakery? Thank you! I appreciate the feedback and review, Anita.
Hello
I will start by saying that I love all your recipes and I thinks it’s fantastic that you add possible substitutions!
I want to make your cookies for my grandchildren and I was wondering if I could substitute date puree for some or all of the sugar?
Thanks
I haven’t tried that, sorry! Baking can be tricky.
I will try substituting half with date puree. We’ll see what happens. Thanks!
Mary
These cookies are AMAZING! I used coconut oil in place of butter, brown sugar, and a vegan egg substitute rather than eggs. I forgot to buy M&Ms so just doubled the amount of chocolate chips. Delicious and addicting! They are super peanut butter-y, which I love. A word of advice – leave the cookies to cool on the baking sheet for at least the full 10 minutes (per Kate’s instructions) before moving to a cooling rack. I got impatient and tried to move them after about 2 minutes, and they broke apart.
Thank you for sharing, Joni! I know it’s hard, but yes wait until they are cooled.
First time, I ommitted the eggs and my cookies didn’t stay together. I realized that I needed something to bind them. Second time, I added flax eggs. I also noticed that my cookies didn’t spread out in the oven. So I just had to smashed them down before I put them in. Whether they were crumbling or not spreading in the oven, does not matter. Hands down, these cookies taste incredible! Thank you for sharing this recipe.
Thank you for sharing, Leah!
My flatmates are my prime cookie taste testers and they LOVED these. They’re a big fan of your vegan chocolate chip cookies but these went down even better. We concluded this is absolutely the best of everything. I found this recipe super foolproof too, it went exactly as anticipated. I only had very dark brown sugar so mine came out quite dark, I look forward to trying them with golden sugar next time.
I’m glad you found it foolproof, Georgia! Thank you for your review.
Made these tonight with my 3 year old assistant. A big hit with her dad, too, even though he is skeptical of cookies with oatmeal (he had 3!). Very delicious and easy to make. I used old fashioned oats, brown sugar, and Easter M&Ms. :) Thanks for the great recipe!
I bet your assistant was a great helper! Thank you for sharing, Lauren.
These are awesome! I used natural peanut butter (stirred well) and they turned out beautifully. Nice and chewy, great texture.
I’m so glad you liked them, Diane!
Okay, this is the absolute best cookie recipe I have EVER had!!! I made it vegan using flax eggs, but the dough turned out really crumbly and I just ended up pressing it down on the baking sheet and making bars. Maybe the peanut butter I used made it dry (I was at the end of a jar of natural peanut butter, and the bottom always has less oil)? We ended up just eating it in a bowl with a spoon and it was amazing! Regardless of the texture, this recipe was a hit and my family ate it in one evening. I’ll try it again once we get more peanut butter, and see if the texture will work better for me.
Thank you for sharing it worked well vegan, Rachel!
This is seriously the best cookie recipe I have ever found!! I am so thankful I stumbled across Cookie & Kate…
I’m so happy you stumbled too, Abigail! Thank you for your review!
Do you think I could make a oatmeal raisin cookie out of this recipe? Like not put peanut butter in and up the oats, and instead of m & m’s /chocolate chips I could try raisins? What do you think?
Made these just the other day. SO good! I used Truvia instead of the coconut sugar and used peanut butter chips instead of the M&Ms. YUM.
I’m sending some to a few special clients too.
I made this recipe again and the cookies actually blew my mind! My best friend who sampled them with me was genuinely speechless.
This time I used half dark brown sugar and half light brown sugar with about some white sugar mixed in. Last time I only had dark brown sugar in my cupboard. I also used 1 tsp baking power and 1 tsp bicarbonate of soda, where last time I used 2 tsp baking powder. The cookies were light fluffy, spread evenly and beautifully, they were soft in the middle (we were too impatient to let them cool) but golden on the outside.
I’m utterly in love with this recipe, and I can’t wait for my family to try the cookies when I go home this weekend!
I’m glad you love it! Thanks for sharing the changes you made, Georgia!
I made these cookies yesterday and they turned out totally flat, I have no idea why… (I didn’t forget baking soda, I swear!) Any idea why this happened? I put the dough in fridge and am going to try again tonight.
Hi Morgan! These don’t get as fluffy like other cookies. But, you may want to make sure you aren’t making them too, big. How did the second batch turnout?
Hi Kate,
I made these cookies again, this time with sunbutter. I reduced the baking soda by half (so, I used just one teaspoon), after reading the advice on sunbutter’s website to reduce baking soda by a third.
I can say they are definitely NOT green and they are delicious! I like these cookies best with dried fruit (I used dried apricots this time) – they seem to be less sweet and a little more chewy. And of all the ‘nut butters’ I like the taste of cashew butter the most, but for a family with allergies, sunbutter is a very good alternative.
I have made these cookies several times and they have always turned out perfect! This time I used a different natural peanut butter and the cookie dough was very wet and the cookies are flat and huge! I would not recommend using a natural peanut butter that needs stirring!!
I’m glad they worked so well for you! Unfortunately, natural peanut butter isn’t all the same with its oil content and stirring needs. Thanks for sharing your experience! I’m sorry that round didn’t turn out.
Love the recipe. Tried to do it egg free and it definitely needs something to bind it. Was going to try flax seed and water next time. Will keep you posted.
Please do! Let me know what you think.
I tried this recipe and it’s fantastic. Even my husband loves them. And he is not a sugar fan.
I am ready for the maple syrup recipe.
Will let you all know.
Thank you for your comment and review, Monica!
Made these tonight, sticking with the original ingredients, and I must say they are DELICIOUS! You definitely need to be patient and let them cool on the cookie sheet for a while or they will stick/fall apart but other than that they are a perfect recipe for kids and adults alike! Can’t wait to make them again with different mix-ins! Thanks for the great addition to my cookbook!
You’re welcome, Shantelle!
WHY IS IT THAT CHOCOLATE CHIPS NEVER STICK TO THE BATTER WHEN USING PEANUT BUTTER AND COCONUT SUGAR?
Hi Kerry, I find it’s a matter of folding the ingredients together. You may have a few stragglers at the end but I just press them down into some cookies prior to baking.
This has become my go-to cookie recipe. The first time I made it I used rolled oats and they turned out ok, but I tried them again with with quick oats, which I think incorporate much better into the cookie. They really soak up the liquid so the cookies come out perfectly puffed up, and chewy on the inside. I’ve made them several times since and they’re consistently amazing!
Great to hear, Allison! I do love these too.
I came across this recipe when looking for a healthier version of monster cookies. I love your focus on healthy ingredients! However, we have no need to be gluten free, and I didn’t realize that it was such a focus for these until I was halfway through making them. It was very hard to form cookies: the “dough” didn’t hold together at all, even when my daughter and I squeezed the cookies into shape on the cookie sheet. Upon tasting, I found them exceptionally sweet and hard to eat because they easily fell into pieces. The crispy edge was great and I loved the flavor from the coconut oil and sugar. I think if I remade them, I’d use less sugar and add at least 1 1/2 cups of flour.
That’s strange! What oats did you use and chocolate add-in? I’m sorry you didn’t love these.
Thanks for the reply! I used old fashioned oats. We love chewy oatmeal cookies, but the oats didn’t really cook, so the cookies hurt your jaw if you eat two in a row. I used 3/4 cup of Ghirardelli semi sweet chips and 3/4 cup of Sweet Nothings M &Ms.
I made these for a large family event this weekend and they were a HUGE hit! Thank you!! My family dubbed them ‘healthy’ thanks to the oats :)
You’re very welcome, Mackenzie!
OMG the cookies were a hit at home!! Will be making them again for sure, but going to make them smaller .
Thank you, Dalia!
These cookies are the BOMB! I have been making different monster cookies for years and tried yours, as I was needing to make them GF and DF. I used brown sugar, coconut oil and DF chocolate chips and upUnreal “M&M’s”. So good! I was taking a pan out of the oven and the parchment paper went flying and parts of cookies fell on the floor. They still taste great off the floor too!♀️. These cookies are so gooey! Try them, you won’t be disappointed.
Well, thank you Kathy! I’m so happy you loved them. Thanks for sharing.
Just made these for a Fall Festival at our church. They look amazing and I’m sure the kids will love them. I used real butter and brown sugar and Reece’s Pieces instead of M&Ms. They are huge! I hope moms don’t let the kids eat a whole one! :-) (I’m a grandma so I can!)
Love to hear that! I like your variation, Carol.
Hi, I just ran out of my brown coconut sugar and still need 1/2 cup of sweeter. The only thing I have in the house is maple syrup, honey and Swerve (erythritol). Any suggestions please?
I don’t think that will work, sorry! Your cookies won’t turnout the same.
To be honest, I didn’t like how these cookies came out. I was a bit disappointed. I could have gotten the measurements off but the texture of the cookies was very coarse but chewy somehow. I was expecting a soft cookie. Also, mine expanded a lot, not just a bit so they were enormous.
Hi Angela, I’m sorry you were disappointed by these cookies. What type of oats did you use and sugar? They are big cookies, but shouldn’t be completely flat.
Do you know if these freeze well?
Hi Erika! I believe readers have liked these frozen. Just be sure to let them cool completely!
Thank you for this awesome recipe! I’m gluten-free, and I was so happy to be able to bake something without weird rice flours and xantham gum. These cookies are delicious!
I’m happy you loved them, Heather!
Hi Kate! I made the dairy free, coconut sugar, and all chocolate chips version for some friends coming into town and this recipe is super delicious! I knew whenI tasted the batter and it reminded me of reese’s pieces candy that I had something extraordinary on my hands, and the aroma while baking draws everyone to the kitchen.
I can’t wait to try these again soon with the hard shell candies for color. The pictures look great. Thank you!!!
I’m glad you loved them! Thank you for sharing, Lisa.
Good morning! Thank you for the wonderful recipes that you provide your followers! This recipe “hits the spot” with my daughter, as she has been diagnosed with a tick borne illness called Alpha GAL. Ingesting meat, dairy or any substance that contains by products of these foods can potentially cause her to have an anaphylactic reaction. After trying many dairy free chips, we found that Nestle’s dairy free dark chocolate chips are the very best for this perfect cookie. Again, I thank you and my daughter thanks you!!
That’s great to hear, Susan! Thanks so much for your review.
These were delicious! I followed the recipe and made half-size cookies – they were plenty big enough so be aware the cookies will be massive if you make 18 as the recipe suggests. I did overbake mine slightly (user error) – trust Kate’s recommendation of 6-9 minutes for half-sized cookies. Next time i would use all m&ms as they look nicer than the chocolate chips. I could not mix all the chips into the batter but dotted the extra chocolates onto the balls once formed.
Hi there, I’m excited to make these cookies! I’m a little confused about the peanut butter amount though. Your recipe says: 1 ½ cups creamy or chunky peanut butter (that’s one full 16-ounce jar minus ¼ cup), but wouldn’t 1 ½ cups be a full 16 oz jar minus ½ cup? Since 1 ½ cups is 12 oz, not 14?
Hey Elizabeth, good question! So, you’re going by the weight of water (8 ounces per cup) and peanut butter is heavier. The amounts provided here are correct.
Gotcha! Thanks for the explanation! My family and I loved these! Making another batch to help us through these weeks home!
You’re welcome, Elizabeth!
The end result of my efforts in following this recipe were delicious. However, my emphasis for this is the effort side of things.
I had to use 3 cups of quick oats; only had good ol’ Kraft Smooth PB, and subbed flax eggs. The mixture ended up being quite like greasy taffy, really had to work at getting everything mixed by hand, my stand mixer couldn’t handle all the sticky. I also could not get all the mini chocolate chips and mini m&m’s to incorporate completely, no matter how hard I tried. I had about 1/4 cup of greasy chips and candies at the bottom of my bowl, and the last 2.5 sheets of cookies have A LOT of choc chips/m&ms piled on.
If I were to make this again, given would likely be using mini choc chips and mini m&m’s, I’d half the measure of each, and that would likely cut down on that issue I had. These cookies are enormous, which helps keep you at just one I guess, and my kids only eating like a 1/4 of a cookie. I might revisit this recipe one more time, as they are delicious, but unlikely that it’ll be on heavy rotation.
How would you adjust using monk fruit erythritol brown sugar? Any thoughts about that as a sweetner?, never tried.
I haven’t, sorrY!
Thank you for the recipe, Kate! As most have said, these are probably the most delicious Cookies we’ve ever eaten! <3
Awesome recipe, our toddler loved them so much(less sugar next time!) and helped me make these delicious cookies. Thanks for sharing Kate! :)
I would love to try this recipe. We have recently moved to Colorado so I’m new to high altitude baking. Can you please suggest any necessary changes.
I split the dough and added chocolate chips and Smarties to half. Raisins and walnuts to the other half. They were amazing. April cooking 2020 for the win.
Really glad to hear it, Kari! Thank you. :)
So amazing! I used 1 cup brown sugar and 1 cup white sugar only because I didn’t have enough brown lol I used almond butter (peanut allergy) and skor bites instead of m&m’s again because its all I had! These are absolutely amazing and only 165 calories each! Thank you so much!!!
This recipe is trash. Dough way to wet, had to bake them way longer than stated and finished cookies were completely flattened.
The cookies were nice and pufffy when they came out of the oven, then they flattened out.