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A stack of peanut butter monster cookies on a white cookie sheet.

Triple Peanut Butter Monster Cookies

Triple Peanut Butter Monster Cookies have three different kinds of peanut butter stuffed inside a delicious, soft-baked monster cookie. Creamy peanut butter, peanut butter chips, and Reese's Pieces make these oatmeal monster cookies a hit with all the peanut butter lovers. 
Course Dessert
Cuisine American
Keyword monster cookies, peanut butter cookies, triple peanut butter monster cookies
Prep Time 15 minutes
Cook Time 10 minutes
Total Time 25 minutes
Servings 12 large cookies
Calories 389kcal


  • ½ cup (1 stick) salted butter softened
  • 1 cup brown sugar
  • ½ cup creamy peanut butter
  • 1 large egg
  • 2 teaspoons vanilla extract
  • cups quick oats
  • ¾ cup all-purpose flour
  • 1 teaspoon baking soda
  • 1 teaspoon cornstarch
  • ¼ teaspoon baking powder
  • teaspoon salt
  • 1 cup peanut butter chips
  • ½ cup mini reese's pieces


  • Preheat oven to 350° and line 2 cookie sheets with parchment paper or a silpat. You can also spray with cooking spray.
  • In a large bowl with a hand mixer, or use a stand mixer with the paddle attachment, add the butter, brown sugar, and peanut butter. Beat on medium-high speed until lighter in color and fluffy looking, about 1-2 minutes.
  • Add the egg and vanilla extract. Beat until combined, scraping down the sides of the bowl as needed.
  • Add the oats, flour, baking soda, cornstarch, baking powder, and salt. Mix on low speed just until combined.
  • Stir in peanut butter chips and reeses pieces.
  • Use a ¼ cup measurer to measure out the cookies. Roll into a ball and place them on the baking sheet. Six cookies per cookie sheet.
    With the bottom of a measuring cup (I use a 1 cup measurer) gently press down the dough balls to form a very thick cookie shape (like a hockey puck). They will not spread much while baking.
  • Bake the cookies for 9-12 minutes until the edges are just starting to lightly brown and the top still looks slightly undercooked.
  • Remove from the oven and cool for at least 15-20 minutes on the baking sheet before moving them to a wire rack to cool completely.
  • * If wanted, press a few additional Reese's Pieces and/or peanut butter chips onto the tops of the cookies. This makes them look pretty!


SALT & BUTTER : If you use unsalted butter you might want to increase the salt to ¼ teaspoon.
REESE'S PIECES : You can find the baking Reese's Pieces in the baking aisle. They are mini size. Or, just use the regular sized Reese's Pieces. I've used both kinds and I prefer the miniature Reese's Pieces. You can sometimes also find them in the ice cream topping area of the store. 
OATS : I prefer quick oats in this recipe because they are a finer/smaller texture. You can use old-fashioned oats but I find that the cookies hold together better with the smaller quick oats. 
PEANUT BUTTER : Use creamy peanut butter only please! It's also best to not use all-natural peanut butter as it tends to dry out cookies because it's drier with not as much oil/fat/creamy texture as regular peanut butter. 


Calories: 389kcal | Carbohydrates: 45g | Protein: 9g | Fat: 20g | Saturated Fat: 11g | Polyunsaturated Fat: 2g | Monounsaturated Fat: 5g | Trans Fat: 1g | Cholesterol: 37mg | Sodium: 311mg | Potassium: 183mg | Fiber: 3g | Sugar: 29g | Vitamin A: 256IU | Calcium: 39mg | Iron: 2mg