Embrace your inner Cookie Monster with these M&M and chocolate chip laden Monster Cookies that are also loaded with plenty of chewy oats and creamy peanut butter! Just try your best to resist the dough so you can actually bake some of these first!

We bake a batch of cookies every week! Some of our other favorites are Andes Mint Cookies, Soft Banana Pudding Cookies and classic Snickerdoodles!

Homemade monster cookies cooling on a rack.

Table of Contents
  1. What are monster cookies?
  2. What are monster cookies made of?
  3. How to make monster cookies
  4. Who invented monster cookies?
  5. Can I use old fashioned oats instead of quick oats?
  6. Can I freeze monster cookies?
  7. More cookie recipes
  8. Monster Cookies Recipe

Monster cookies are a fun and fantastic way to get all of your favorite cookie experiences in one. They’re a combination of your favorite Peanut Butter and M&M cookies, and Oatmeal Chocolate Chip Cookies all rolled into one. With so much going on in every bite it’s a perfect blend of happiness.

What are monster cookies?

Personally, I think the best reason for calling these monster cookies is their massive size. They are monster-sized cookies for sure if you make large balls of dough!

But another theory for the name is that monster cookies are a hybrid of a few other cookies rolled up in one. Sort of like Dr. Frankenstein's monster, these cookies pull together bits and pieces of various recipes and make one unique creation.

What are monster cookies made of?

Monster cookies are made using a combination of basic brown sugar cookie dough, chocolate chips, peanut butter, oats, and M&Ms.

Of course several other optional mix-ins can include shredded sweetened coconut, butterscotch chips, chopped peanuts, or even broken pretzel pieces for a salty/sweet combination!

Peanut butter oatmeal monster cookies on parchment paper.

How to make monster cookies

  1. Prep: Preheat your oven to 350F degrees and line two baking sheets with parchment paper. Set them aside.
  2. Cream butter and sugar: In the bowl of a stand mixer, beat together the butter, the peanut butter, and the sugars until creamy and light, about 2 minutes.
  3. Mix some more: Add in the eggs and the vanilla, and beat again. Scrape down the sides of the bowl often and mix until everything is combined.
  4. Add in dry ingredients: Mix in the oats, flour, baking soda, and salt until just combined. Don't overmix though or you will end up with dense, tough cookies. Stir in ¾ cup of the mini M&Ms and the chocolate chips.
  1. Scoop: Use a large cookie scoop (¼ cup sized) to scoop the dough into large mounds of dough on the prepared baking sheets. You should be able to fit about 8 cookies per sheet. Remember to space them out so that the cookies can spread a bit without sticking. Press some reserved M&Ms onto the tops of the cookies.
  2. Bake: Bake in the oven for 10 minutes or just until they become set around the edges. Do NOT over bake these cookies, they will appear slightly underdone and will continue to set up as they cool.
Eight balls of monster cookies dough on a baking sheet.
  1. Garnish: Immediately press the reserved chocolate chips onto the cookies and then transfer onto a wire rack to cool completely.
Large monster cookies on a wire rack with mini M&Ms.

Who invented monster cookies?

Monster cookies were originally created in 1971 by Mr. Dick Wesley, a University of Michigan photographer. He was the father of 6 kids and constantly trying to find new ways to use up what they had on hand. His original recipe included candy coated chocolates (like M&Ms) as well as leftover jam that the kids weren’t eating fast enough.

He also blended oats to create a flour base, instead of using actual flour. As you can see, the recipe has since been modified quite a bit as time went on. Most versions these days have abandoned the jam and oat flour base in favor of a mix of oats and all-purpose flour.

Cookies with chocolate chips and mini M&M's.

Can I use old fashioned oats instead of quick oats?

Yes, you can. Using them as-is will create chewy oats because they won’t fully cook and soften during the baking process. To use them and get them into a more enjoyable texture, I recommend placing the oats in a blender or a food processor (affiliate link) and then pulsing them a few times to chop them up into smaller pieces first.

Can I freeze monster cookies?

Yes, these cookies are great for freezing. Simply let the cookies cool completely and then place them in an airtight container in the freezer for up to 6 months. Remove a cookie and let it thaw on the counter for about 30 minutes before eating so that they aren’t rock solid.

Did you make this recipe?

Let me know what you thought with a comment and rating below. You can also take a picture and tag me on Instagram @houseofnasheats or share it on the Pinterest pin so I can see.

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Monster Cookies

5 from 10 votes
Amy Nash
Prep Time 10 minutes
Cook Time 10 minutes
Total Time 20 minutes
Course Cookies
Cuisine American
Servings 12 -14 large cookies
Embrace your inner Cookie Monster with these M&M and chocolate chip laden Monster Cookies that are also loaded with plenty of chewy oats and creamy peanut butter! Just try your best to resist the dough so you can actually bake some of these first!


  • ½ cup salted butter softened
  • 1 cup creamy peanut butter
  • ¾ cup granulated sugar
  • ¼ cup light brown sugar, packed
  • 2 large eggs
  • 2 teaspoons vanilla extract
  • 1 cup all-purpose flour, scooped & leveled (141g)
  • 1 teaspoon baking soda
  • 1 teaspoon cornstarch
  • ½ teaspoon table salt
  • 1 ½ cups quick oats
  • 1 cup mini m&m's divided
  • ¾ cup semisweet chocolate chips divided


  • Preheat oven to 350 degrees F. Line two baking sheets with parchment paper.
  • In the large bowl of a stand mixer, beat the butter, peanut butter, and sugars on medium-high speed for 2 minutes until creamy and light.
  • Add eggs and vanilla and beat again, scraping the sides and bottom of the bowl until everything is combined.
  • Add the oats, flour, baking soda, cornstarch and salt. Mix just until combined.
  • Stir in ¾ cup each of the mini m&m's and chocolate chips.
  • Use a large ¼ cup cookie scoop to scoop mounds of cookie dough onto the prepared baking sheets, about 8 cookies per sheet. Space them out so they can spread a bit without touching. Press the reserved m&m's into the tops of each cookie.
  • Bake for 10 minutes, just until set around the edges. Do NOT overbake these cookies. They may look slightly underdone, but they will continue to set up on the pan. Immediately press a few of the reserved chocolate chips into the top of each cookie. Transfer the cookies to a wire rack to cool completely.



  • If you don't have quick oats on hand, you can use old-fashioned oats. Just pulse them in a blender or food processor (affiliate link) a few times to chop them a bit smaller first.


Calories: 500kcal | Carbohydrates: 54g | Protein: 10g | Fat: 28g | Saturated Fat: 12g | Polyunsaturated Fat: 4g | Monounsaturated Fat: 9g | Trans Fat: 1g | Cholesterol: 51mg | Sodium: 380mg | Potassium: 270mg | Fiber: 4g | Sugar: 34g | Vitamin A: 320IU | Vitamin C: 1mg | Calcium: 53mg | Iron: 2mg
Tried this recipe? Show me on Instagram!Mention @HouseOfNashEats or tag #houseofnasheats!

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About the author

Hi, I'm Amy

I enjoy exploring the world through food, culture, and travel and sharing the adventure with mostly from-scratch, family friendly recipes that I think of as modern comfort cooking.

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Reader questions and reviews

  1. A delicious recipe with all of the best ingredients for Monster Cookies! Love how big and all of your great tips for the chewiest, most colorful cookies! Making these to send my son in college!

  2. Oh, my word!! These indeed surbed my inner cookie monster!! They have everything that a cookie needs to be perfect in my book! Thank you!

  3. When i saw the photo today, I was scrolling down to be big-shot knowing the monster history. I had this in winter of 1979 near Flint Michigan and it was either in Ma's Family Circle or Womens Day. I read here mine is not original made 1971. Might of gotten it somewhere local, the old recipe card sharing was still going strong in the Midwest. They were called Cowboy cookies; a bit less candy on top. For a couple years I have been huge fan of the Nash peanut butter oatmeal. It was fun to see new people find it because they had gotten the ingredients in a relief box and needed a way to use them.

  4. I see cornstarch in the list of ingredients but I do not see it in the directions.
    just making sure its needed and its not a typo.

    1. You can definitely skip it, but it makes for a softer cookie. It goes in at the same time as the baking soda, flour, and salt.

  5. I put them on the baking sheet in clumps with the 1/4 cup but they didn’t spread when I put them in the oven, like they stayed in a ball… I had to push them down. Do you know what I could of done wrong? 🥴🫣

    1. Hmmm I am not quite sure but some culprits could be too much flour, the oven wasn't hot enough when you put the cookies in, the dough was too chilled? Even adding a little but more white sugar can help your cookies spread. You could even push the dough down a little flatter before baking. Hope that helps! Try again and Let me know how they turn out!