Monster Cookies

4.67 from 3 votes

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Monster Cookies are like three cookies all rolled into one(Oatmeal Cookies, Peanut Butter Cookies, and Double Chocolate M&M Cookies)! Filled with oats, peanut butter, and M&Ms, these will have you coming back for more. All the goodies we love about cookies in one glorious sweet treat!

Monster Cookies on a baking sheet

I am so happy to be sharing these Monster Cookies with you today! My husband goes crazy over these and for good reason, too! Everything we love about cookies at our house are all thrown together in one amazing cookie dough and baked to give you lots of soft, chewy peanut buttery chocolatey cookies with that great texture you can only get from oats. Give these a try today! They are so so good.

Do your significant others ask you to make cookies just so they can have some cookie dough to munch on? MINE DOES! Oatmeal Cookies and Peanut Butter Cookies are his favorite kinds of dough to snitch but the other day, he was asking me for “those cookies with all the things in them”. After doing a little more digging, I realized he meant Monster Cookies!

Y’all, this kind of cookie needs a spot in your recipe box asap. It’s got oats, butter, peanut butter, two kinds of sugar, M&M’s, and a few other necessary cookie ingredients like flour and baking soda. Everything besides the M&M’s are things I have in the cupboard on the regular, so these can be made in a snap when the craving hits.

Main Ingredients Needed

Here is everything you’ll need to make these Monster Cookies:

  • Salted Butter – be sure to plan ahead and have this softened! Gives flavor and texture to the cookies.
  • Peanut Butter – you can also use crunchy peanut butter if you want more of a crunch. For natural PB see below!
  • Granulated + Brown Sugar – both are used to sweeten but brown sugar keeps these cookies soft.
  • Eggs – for structure and texture.
  • Vanilla + Salt – for flavor.
  • Flour – fills out the cookies. For correct measuring techniques, see below under Fluff Your Flour.
  • Baking Soda – this is used as our leavening agent.
  • Rolled Oats – this gives the cookies even more texture while also absorbing flavor.
  • M&M’s – I used mini M&M’s and they were perfect. I love the slight crunch you get from the outer coating.
Monster Cookies on a baking sheet

Can I use natural peanut butter?

Yes, but there’s a caveat. Natural Peanut butter is basically just ground peanuts and salt which is delicious as is, but not as good to use in a ‘butter’ application like a JIF or Skippy would be. Getting the perfect cookie dough that spreads (but not too much!) comes down to balancing the right amount of fat with the right amount of flour. Natural Peanut Butter messes with this ‘balance’.

If you are going to use all-natural peanut butter, be sure to reduce the flour amount by 1/4 cup. That should help create the kind of cookies pictured in this post. Not all-natural peanut butters are created equal and if you haven’t mixed it evenly before use, you can get a greasier (at the top of the jar) or crumbly peanut butter (bottom of the jar). This can prevent you from getting picture-perfect Monster Cookies. So, I’m not saying DON’T use natural peanut butter, I’m just pointing out that you should process with caution.

If you bake one cookie and it hasn’t spread, simply press your cookies out before baking. If it spreads out too far, add in 1-2 more tablespoons of flour.

Do I have to use salted butter?

I am definitely in the minority when I say I test 99% of my baked goods with salted butter. I think it balances out desserts better and I simply just like it better. However, if you only have unsalted butter, don’t let that stop you from making this monster cookie recipe. Simply add in an additional 1/2 teaspoon of salt to the cookie dough (so it becomes 1 teaspoon of salt total in this recipe).

Monster Cookies stacked on top of each other

How to Make Monster Cookies | Directions

The process is just like any other you would follow when making cookies. I use the creaming method to get this dough together in about 10 minutes tops. For the exact measurements and more specific directions, be sure to scroll down to the printable recipe card at the bottom of this post. Also! Be sure to read my notes below about natural peanut butter for creating the best monster cookies!

1. Preheat + Prep

Preheat oven to 350 degrees. Line two light-colored baking sheets with parchment paper and set aside.

2. Make Cookie Dough

Cream butter, peanut butter, brown sugar, and granulated sugar together until light and fluffy. Add in eggs and vanilla and stir again. Scrape the sides well and mix.

Slowly stir in flour, baking soda, and salt. Again, scrape the sides and the bottom of the bowl to ensure an evenly mixed dough. Add M&Ms in and stir by hand.

NOTE: Fluff Your Flour

I get so many comments and angry emails every week from people saying “my recipes suck” because their cookies came out “like rocks” or their cookies were “like buttery flat pancakes”. This comes back to the balance of fat and flour. All cookies are the same! They need the right balance to work. The best way to get this balance is to measure your flour correctly. How do you do this? Fluff your flour: measure it into your measuring cup and dump it out 3-4 times to aerate it, spoon it into your measuring cup and then level the top. That is the correct way to measure flour and how I measured it for these monster cookies.

3. Bake + Cool

Scoop cookies onto baking sheets and bake 8-9 minutes. Cool slightly on hot baking sheets before transferring to cooling racks.

I like making larger cookies using a 3 tablespoon large cookie scoop, but any size cookies are fine! I got 24 large cookies using my cookie scoop.

close up of a monster cookie

If you loved these Monster Cookies you’re going to love my other candy-filled cookies.

The printable recipe card is below, happy baking!

Monster Cookies
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4.67 from 3 votes

Monster Cookies

Monster Cookies are like three cookies all rolled into one! Filled with oats, peanut butter and M&Ms, these will have you coming back for more.
servings 24 cookies
Prep Time 15 minutes
Cook Time 10 minutes
Total Time 25 minutes



  • Preheat oven to 350 degrees. Line two light-colored baking sheets with parchment paper and set aside.
  • In a large bowl, cream butter, peanut butter, sugar, and granulated sugar together until light and fluffy. Stir in eggs and vanilla. Scrape the sides and stir again briefly.
  • Stir in flour, baking soda, salt, and oats until just incorporated. Scrape sides and bottom of the bowl and stir again briefly. Stir in M&M's by hand.
  • Scoop cookie dough into large 3-tablespoon mounds and place onto baking sheets. Bake 8-9 minutes or until edges are lightly golden and cookies are puffed. Cool 3-4 minutes on the hot baking sheet before transferring to a cooling rack.


If you are going to use all natural peanut butter, be sure to reduce the flour amount by 1/4 cup.


Calories: 241kcal | Carbohydrates: 37g | Protein: 4g | Fat: 9g | Saturated Fat: 4g | Cholesterol: 27mg | Sodium: 128mg | Potassium: 77mg | Fiber: 1g | Sugar: 25g | Vitamin A: 165IU | Vitamin C: 1mg | Calcium: 29mg | Iron: 1mg
Course: Dessert
Cuisine: American
Keyword: how to make monster cookies, monster cookie recipe, monster cookies
4.67 from 3 votes (1 rating without comment)

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Recipe Rating

5 Responses
  1. Kate

    I was so excited to try this recipe! I made them exactly how the recipe states and when I took them out of the oven they looked beautiful – after leaving them on the cookie sheet to cool for 4 minutes, every cookie fell and became flat saucers with hunks of M&M’s in them! I fluffed the flour, as instructed. So disappointing! What happened?

  2. Ellen-Ann Robinson

    4 stars
    I weigh my Flour as I make a lot of bread but I can fluff it up. I haven’t made these yet but would be fun for the 4th with red, white and blue M+M’s.

  3. Tina

    5 stars
    OK seriously took eight minutes to do and my son help me and he likes the brown sugar and white sugar and we eat a bunch of M&Ms as we were making this. I’ve probably been following you for a solid five months and made eight of your recipes so far especially during this Covid and I got to tell you your food recipe tasty it’s amazing my boys love it we love it thank you for making it simple and easy. By the way I made your cheesecake two days ago and it was a hit I have like two slices left I did the basic plain one but next time I might do the strawberry one.