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These Thick and Chewy Monster Cookies are loaded with peanut butter, oats, M&M's and chocolate chips. They’re a cross between a chewy oatmeal chocolate chip cookie, and a peanut butter cookie, and they’re sure to be a huge hit with family and friends.
I LOVE making cookies, and since I don't usually have fresh-baked cookies available on the spot, I like to freeze them for when friends come over or when we just want a little treat. In my freezer currently are Jumbo Chocolate Chip Cookies, Red Velvet Sandwich Cookies, and Chewy Pumpkin Chocolate Chip Cookies. Who wants to come over?!
Monster Cookies
Don't ask me to choose a favorite type of cookie because I just wouldn't be able to! There are too many fun variations. These Monster Cookies are always popular and I love the great texture from the oats and the subtle peanut butter flavor.
Why are they called Monster Cookies?
There’s not an exact answer for why these cookies are called “Monster” Cookies. Some people think it’s because they look like monsters, with their bumpy texture and fun colors. I like to think it’s because they’re stuffed with so much “stuff”, making them the “monster” of all cookies.
Whatever the reason, all Monster Cookies have these ingredients in common: peanut butter, oats, chocolate chips and m&m chocolate candy.
How to make Monster Cookies:
- Cream the butter and sugars. Use REAL butter and cream it with the sugar for at least 2-3 minutes until really light and fluffy. This is adding air to the mixture and is the base for the texture we want in our cookies.
- Mix wet ingredients. Add the peanut butter and mix well. Add egg and vanilla and mix.
- Measure flour properly and mix dry ingredients. When measuring the flour be sure to fluff it a bit first, allowing air to fill in (like sifting) before you spoon it lightly into the measuring cup. Stir together the flour, oats, salt, baking powder and baking soda. Stir into wet mixture with m&m's and chocolate chips.
- Slightly under-bake. Bake at 350, being careful not to over bake the monster cookies. The tops will look just set and they will continue to harden and set up as they cool on the baking sheet.
How do I keep my cookies from spreading?
During baking, cookies naturally spread, but the key is to make sure they don't spread too much. To keep your monster cookies from spreading, be sure to use exact measurements (no guesstimating) and use room temperature ingredients, particularly the butter and eggs. You can also stop cookies from getting flat by chilling the dough for 15-30 minutes before baking.
Storage and Freezing Instructions:
These cookies will keep well in an air-tight container for 1-2 days, or you can freeze the cookie dough or baked cookies. To freeze them after they’re baked, allow them to cool completely and store them in a freezer safe container for up to 3 months. Freeze cookie dough balls in a freezer safe container and when ready to bake, place the frozen cookie dough on a baking sheet and add 2-4 minutes to the baking time.
CONSIDER TRYING THESE POPULAR COOKIE RECIPES:
- Jumbo Chocolate Chip Cookies
- Super Soft Sugar Cookies
- Triple Chip Blondies
- M&M Cookie Bars
- Chocolate Mint Cookies
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Thick and Chewy Monster Cookies
Equipment
- Stand Mixer optional
Ingredients
- 1/2 cup butter
- 1/2 cup granulated sugar
- 1/2 cup light brown sugar
- 1/2 cup peanut butter
- 1 egg
- 1 teaspoon vanilla extract
- 1 cup all-purpose flour
- 1 1/4 cups old-fashioned rolled oats
- 1/4 teaspoon salt
- 1/2 teaspoon baking powder
- 1/2 teaspoon baking soda
- 3/4 cup M&M candies
- 1/2 cup semi-sweet chocolate chips
Instructions
- Preheat oven to 350 degrees F.
- Cream the butter and sugar together really well—at least 2-3 minutes until light and fluffy.
- Add peanut butter and mix well. Add egg and vanilla and mix.
- In a separate mixing bowl stir together the flour (be careful to measure correctly, spooning the flour into a measuring cup, then leveling off), oats, salt, baking powder and baking soda.
- Add to the wet mixture and mix to combine. Stir in chocolate chips and M&M’s.
- Bake at 350 degrees for 10-12 minutes, or a little longer if you make them bigger than a 1 inch cookie scoop. Don't over bake--they will look just set.
- Remove them from the oven and allow them to cool completely on the pan.
Notes
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
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HAVE YOU TRIED THIS RECIPE?!
RATE and COMMENT below! I would love to hear your experience.
OMG, these cookies are to die for. 10/10 would recommend. the only part I regret is eating them all. haha 😅
How many tablespoons per cookie?? I wish she would clarify the instructions.
I’m so sad I didn’t bake a double batch 😭
I should have never made these cookies because they are so so delicious and I will eat them all!!
Every year I do a “bake off” where I try several recipes of the same type of cookie. This year was monster cookies, and this came out the winner! Best of the top four recipes on the internet. Thanks for sharing!
BEST MONSTER COOKIES EVER! They’re crisp on the outside and chewy on the inside. We used the pack of M&M’s with peanut, peanut butter, and regular in it and it was a great choice.
I love monster cookies so much and these are delicious. Nice and chewy they don’t get hard if they sit out or in the fridge. They’re literally perfect.
I have made this recipe so many times and decided it was time to comment. These are the best monster cookies. thank you. we make them all the time.
These turned out great!
Everything I used was measured out and room temp, I mixed all the wet ingredients into the flour and then added the oats & chocolates at the same time so I didn’t overmix. I also chilled for 20 minutes before scooping into 1 inch balls and then flattening into disks.
Definitely pull them at 10-12 depending on your oven and let them keep cooking on the sheet. Very moist & tasty! They didn’t last long at my house.
Thank you!!
We like these cookies and found the taste and texture good. I had the same issue as others while baking with the cookie balls not spreading. I squished the first batch with a few minutes left and flattened the remaining dough balls before baking. Next time, I will not chill the dough and see how it goes. A keeper recipe with just a few tweaks needed to achieve my preferred thickness.
As others stated, I followed the recipe and instructions exactly. They turned out dry and crumbly. Whatever the variable is, it’s a risk not worth taking. Find a different recipe.
I love this recipe qui k and easy and very good
Made this recipe using peanut butter chips and chocolate chunk chips… OH YEAH!
These are so good! I made them twice and the second time added less sugar as they were too sweet the first time but they are such a good balance of all things yummy! We used the Canadian smarties (like m&ms but without food dye) and I can see us making these for years to come.
Huge hit! Simple to make and tasted amazing! Have you tried adding walnuts? If yes, did you substitute something?
Has anyone tried to make this recipe gluten free?
I followed the recipe exactly, except I used crunchy peanut butter, and they’re absolutely delicious! I used a medium cookie scoop, baked for 12 minutes and got 30 cookies from the recipe. The base is so good, I’m thinking about using it and trying some variations (like butterscotch chips instead of the m&ms/chocolate chips). I’ve tried it with smooth and crunchy peanut butter and the crunchy really elevates the recipe, highly recommend!
They taste okay, but are dry and crumbly. They don’t bake well and don’t flatten out. They turned out better when I squished them down a little bit. Won’t be making these again
Oh wow I wonder if it’s your altitude as mine have come out really moist each time I’ve made them and they flatten beautiful, I do use a cookie scoop. I actually was debating using less butter next time because I felt they were almost too moist!
This recipe appeared many years ago in the Woman’s Day magazine. Although the ingredients are all the same, the amounts do vary. They were called Colossal Thick and Chewy Cookies because they were BIG (like monster) The recipe used 1/2C of dough to be flattened out into a 5″ diameter. Optional were 1″ diameter balls, flattened with a glass to a 2″ diameter cookie that baked for 8-10 min.