Thick and Chewy Monster Cookies loaded with chocolate chips, M & M’s, peanut butter, and oats. They take only 20 minutes to make and are perfect for sharing, or you can keep the whole batch to yourself!

Dig into some more big chunky cookies! My Copycat Levian Bakery Cookies are super thick and try my Breakfast Cookies for a treat to wake up to!

Monster cookies on a white plate.

Want to save this recipe?

Enter your email below & we'll send it straight to your inbox! You will also receive other new recipes in your inbox weekly!

    Monster M & M Cookies

    Now, these aren’t just any kind of cookie. They are MONSTER cookies. They are loaded with peanut butter, oats, chocolate chips, and M & M’s. These M & M Monster Cookies are a mix between my Chewy Peanut Butter Cookies and Peanut Butter M & M Cookies. They are super thick, chewy, and loaded with tons of M & M’s and chocolate chips. I slightly under-bake the cookies to get the soft, chewy center.

    This recipe makes about 16-18 pretty good-sized cookies. I like to double or triple the recipe to have some extra to freeze.

    These monster cookies are the perfect blend of soft and chewy. I love the texture of the old-fashioned oats in this cookie.

    They are also a great cookie to load up with any leftover Halloween candy you still have! I love to mix in mini Reese’s cups!

    Hand breaking Monster cookie on a white plate.

    What you’ll need to make Monster Cookies

    • Butter: I used unsalted butter and added salt later. Skip the salt if you add salted butter.
    • Sugar: Just light brown sugar is needed for these Monster Cookies. You could use white or dark brown sugar in a pinch.
    • Peanut butter: Creamy peanut butter gives the best texture. I like to use a brand like Skippy of Jif instead of brands that are 100% nuts.
    • Vanilla: Vanilla brings out the warmth and sweetness of these cookies.
    • Egg: Egg is a binding ingredient, making everything stick together.
    • Flour: Flour is the foundation of most cookie recipes. I haven’t tried gluten-free flour for this recipe yet. Let me know if you do in the comments below!
    • Salt: Just a little seasoning makes the sweetness pop!
    • Baking soda: Baking soda gives the monster cookies a bit of a lift.
    • Oats: I recommend old-fashioned oats, and not steel cut or instant for this recipe.
    • Mix-ins: I mixed in chocolate chunks and m&m’s. Check out my list below for some other ideas!

    How to make Monster M & M Cookies

    • Cream sugar and butter: In a stand mixer with the paddle attachment cream butter and sugar until light and fluffy, about 3 minutes.
    • Peanut butter: Add in peanut butter and mix for 1-2 minutes.
    Cream butter, sugar, and peanut butter in a stand mixer with a white paddle.
    • Vanilla and egg: Add in vanilla and egg. Mix until combined.
    • Combine dry batter ingredients: Combine flour, salt, and baking soda in a small bowl.
    • Mix together: Add the dry ingredients to the batter in two parts with the stand mixer at the lowest speed. Mix for a little less than a minute. Do not overmix.
    Add m&ms and chocolate to the cookie batter.
    • Add chunky ingredients: Fold in old-fashioned oats, M & M’s, and chocolate chips.
    Mix the cookie batter together in a clear mixing bowl.
    • Portion cookies: Portion dough into 16-18 cookies and place on a silicone baking mat on top of a baking sheet.
    Portioned cookies on a baking tray with parchment paper.
    • Bake! Bake monster cookies for 11-13 minutes or until lightly golden brown and firm on the edges.
    • Sit: Remove from the oven and let sit for 3-4 minutes.
    Baked cookies on a tray with parchment paper.
    • Cool: Transfer to a cooling rack to cool completely.

    How long can you store the cookies?

    Cookies can be stored in an airtight container at room temperature for 3-5 days (if they last that long). You can always freeze the cookies for up to 3-4 months.

    What kind of oats can you use?

    I recommend using old-fashioned oats. I do not recommend making these cookies with steel-cut or instant oats.

    What else can I mix into the monster cookie batter?

    • Mini Reese’s
    • Chopped walnuts, pecans, or cashews
    • White chocolate chips
    • Crushed oreo’s
    • Butterscotch chips
    • Peanut butter chips
    • Crushed pretzels
    Monster cookie on a white plate.

    more cookie recipes to try!

    Monster M & M Cookies

    3.84 from 6 votes
    Rate Print
    Thick and Chewy Monster M & M Cookies loaded with chocolate chips, M & M’s, peanut butter, and oats! They take only 20 minutes to make!
    Servings: 16 cookies
    Prep Time: 10 minutes
    Cook Time: 10 minutes
    Total Time: 20 minutes

    Ingredients 

    Instructions 

    • Preheat oven to 350 degrees.
      In a stand mixer with the paddle attachment cream butter and sugar until light and fluffy, about 3 minutes.
    • Add in peanut butter and mix for 1-2 minutes.
    • Add in vanilla and egg. Mix until combined.
    • Combine flour, salt and baking soda in a small bowl.
    • Add the dry ingredients to the batter in two parts with the stand mixer on the lowest speed. Mix for a little less than a minute. Do not over mix.
    • Fold in old fashioned oats, M & M’s and chocolate chips.
    • Portion dough into 16-18 cookies and place on a silicone baking mat on top of a baking sheet.
    • Bake cookies for 11-13 minutes or until lightly golden brown and firm on the edges.
      Remove from the oven and let set for 3-4 minutes.
    • Transfer to a cooling rack to cool completely.
    • Cookies can be stored in an airtight container at room temperature for 3-5 days (if they last that long). You can always freeze the cookies for up to 3-4 months.

    Nutrition Information

    Calories: 303kcalCarbohydrates: 37gProtein: 5gFat: 16gSaturated Fat: 8gCholesterol: 28mgSodium: 160mgPotassium: 140mgFiber: 2gSugar: 24gVitamin A: 221IUVitamin C: 1mgCalcium: 42mgIron: 1mg

    Did you make this?

    I’d love to hear your feedback! Leave a review and make sure to share your pictures on social media! Don’t forget to follow @thechefsavvy.

    Leave a review Follow Chef Savvy