Monster Cookies: peanut butter and oatmeal cookies packed with chocolate chips and colorful M&M's. These cookies are big on flavor and especially fun to make with kids!
Print Recipe
4.75 from 8 votes

Monster Cookies

This easy recipe for the best Monster Cookies yields a soft and chewy mouthful of amazingness!
Prep Time15 mins
Cook Time10 mins
Total Time25 mins
Course: Desserts
Cuisine: American
Keyword: chocolaote chips, cookies, dessert, jumbo, monster cookies
Servings: 30 cookies
Calories: 268cal
Author: Amanda Formaro


  • 1/2 cup butter softened
  • 1 cup brown sugar packed
  • 1 cup granulated sugar
  • 3 large eggs room temperature
  • 1 1/2 cups peanut butter
  • 1 1/2 teaspoons corn syrup
  • 1 1/2 teaspoons vanilla extract
  • 1 cup all purpose white flour
  • 2 teaspoons baking soda
  • 3 1/2 cups old fashioned oats
  • 208 grams M&M candies 1 cup
  • 1/2 cup semi sweet chocolate chips


  • Preheat oven to 350°F. Line cookie sheets with silicone mats or parchment paper; set aside.
  • In a large mixing bowl, cream butter, brown sugar and white sugar with an electric mixer until light and fluffy.
  • Add eggs one at a time, beating until incorporated.
  • Beat in peanut butter, corn syrup and vanilla, mixing well. Stir in flour, baking soda and oats. Fold in M&Ms and chocolate chips, just until combined.
  • If dough is too sticky to handle, refrigerate for at least 30 minutes. Drop 3 tablespoons of dough on prepared cookie sheet, spacing cookies at least 2 inches apart. Press a few extra M&Ms on the tops for more colorful appearance, if desired. Bake at 350°F for 9-13 minutes.
  • Shorter time will result in softer, chewier cookies. Cookies will look slightly under-baked; allow to cool on cookie sheet for 5-10 minutes after removing from oven. Use the longer bake time if the dough has been chilled or crisp cookies are preferred. Cool on cookie sheet for 2 minutes, then remove to wire rack to cool completely.




Because these are called monster cookies, I like to make them extra large-sized – about 3 tablespoons or so. You'll get about 3 dozen with this size. The amount can be adjusted down to 1 1/2-2 tablespoons, which is about the size of a “regular” cookie and you'll get more cookies.


Serving: 1cookie | Calories: 268cal | Carbohydrates: 32g | Protein: 6g | Fat: 13g | Saturated Fat: 5g | Cholesterol: 27mg | Sodium: 174mg | Potassium: 156mg | Fiber: 2g | Sugar: 20g | Vitamin A: 135IU | Vitamin C: 0.1mg | Calcium: 31mg | Iron: 1.2mg