Skip to Content

Monster Cookies

Monster Cookies

These monster cookies are so easy to make and taste fantastic! Loaded with oatmeal, peanut butter, chocolate chips and M&M’s, they’re the perfect treat!

the best monster cookies

These are currently the favourite cookie at my house. Although, to be fair, they probably would have been the favourite long ago if I had made them.

You can’t really beat soft and chewy oatmeal peanut butter cookies that are loaded with both chocolate chips and m&m’s. The kids love them. Almost as much as the adults do.

oatmeal peanut butter cookies

But to be honest, I’ve always just made oatmeal peanut butter cookies instead – heavier on the peanut butter flavour than the chocolate – because I love those cookies too. And m&m’s just aren’t something I keep stocked in my pantry.

I’m thinking they may need to be though, judging by how fast these monster cookies have disappeared when I’ve made them over the last few weeks!

monster cookies

Can you use instant oatmeal in monster cookies?

I don’t use instant oatmeal in this recipe. I think that quick oats would work fine in these cookies though, as this recipe is adapted from my Chocolate Chip Oatmeal Peanut Butter Cookies, which does use quick oats. So if that’s what you have it should be a fine substitute, although I haven’t tried it myself in this recipe.

For these monster cookies, I prefer to use old fashioned rolled oats. The rolled oats give the cookies a thicker, chewier texture than you will get with quick oats.

That being said, I think that quick oats would be tasty in these cookies too if that’s what you have!

monster cookies

How do you make peanut butter oatmeal cookies from scratch?

These cookies are so easy to make from scratch, and are way better than store bought cookies!

A stand mixer with the cookie paddles attached will make very short work of mixing the cookie dough, but if you don’t have one, an electric mixer will work fine for creaming the butter and sugar.

monster cookies

After the wet ingredients are mixed well, you simply mix in the dry ingredients, stir in the chocolate chips and M&M’s, and drop the cookie dough onto a baking sheet.

There isn’t even any need to chill this cookie dough, so you can be eating some delicious monster cookies in less than half an hour!

oatmeal peanut butter cookies

How to make Monster Cookies:

  • These cookies are 1 1/2 tablespoons of batter each, and are made as a drop cookie. A 1 1/2 tablespoon cookie scoop is perfect for dropping the dough onto a baking sheet quickly and evenly.
  • I use mini M&M’s for these cookies, but regular sized M&M’s would be fine here too.
  • Make sure not to over bake these cookies. They will be crispy instead of chewy if you bake them too long. They will still look slightly under done in the middle, with the edges just starting to brown, when you take them out of the oven.

Here are some more great cookie recipes for you:

easy monster cookies
Yield: 24 cookies

Monster Cookies

monster cookies

These monster cookies are easy to make and taste great! Loaded with oatmeal, peanut butter, chocolate and m&m's, they're the perfect treat!

Prep Time 15 minutes
Cook Time 10 minutes
Total Time 25 minutes


  • 1/2 cup unsalted butter, softened
  • 1/2 cup granulated sugar
  • 1/2 cup brown sugar, lightly packed
  • 1 large egg
  • 1/2 cup creamy peanut butter
  • 1 teaspoon vanilla
  • 3/4 cup all purpose flour
  • 1 1/4 cup old fashioned rolled oats
  • 1/4 teaspoon salt
  • 1/2 teaspoon baking soda
  • 1/2 cup semi-sweet chocolate chips
  • 3/4 cup mini M&M’s (or regular M&M’s)


  1. Preheat the oven to 350 degrees F. 
  2. Line 2 baking sheets with parchment paper and set aside.
  3. In a stand mixer, or a large bowl with a hand mixer, cream the butter, sugar, and brown sugar together until light and fluffy.
  4. Add the egg, peanut butter, and vanilla and mix until smooth.
  5. Add the flour, oats, salt, and baking soda and mix until combined.
  6. Stir in the chocolate chips and M&M’s.
  7. Drop the cookie dough onto the prepared cookie sheet, 1 1/2 tablespoons of cookie dough per cookie. 
  8. Bake for 9-11 minutes, just until the middles of the cookies are set and the edges are just starting to brown. Don’t over bake the cookies or they will be crisp instead of chewy.
  9. Let the cookies cool on the baking sheet for 5 minutes before removing them to a wire rack to cool completely. 
  10. Store in an airtight container at room temperature for up to 5 days, or freeze for up to 3 months.

Recommended Products

This post contains affiliate links. As an Amazon Associate, I may receive a small commission from qualifying purchases.

Nutrition Information:



Serving Size:


Amount Per Serving: Calories: 179Total Fat: 9gSaturated Fat: 5gTrans Fat: 0gUnsaturated Fat: 4gCholesterol: 19mgSodium: 83mgCarbohydrates: 22gFiber: 1gSugar: 14gProtein: 3g

Nutrition Information is estimated based on ingredients used and may not be exact.

Skip to Recipe