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Monster Cookies

Monster cookies are thick, chewy peanut butter cookies loaded with M&Ms, chocolate chips, and oats in every bite. Baked until golden at the edges and softly underdone in the center, then cooled so they finish setting.
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Prep Time 15 minutes
Cook Time 12 minutes
Total Time 27 minutes
Servings: 24 servings
Course: Dessert
Cuisine: American
Calories: 210
Ingredients Equipment Method Notes

Ingredients
  

Peanut butter cookie base
  • 1.5 cup creamy peanut butter
  • 1 cup brown sugar, packed
  • 0.5 cup granulated sugar
  • 3 large eggs
  • 2 tsp vanilla extract
  • 1 tsp baking soda
  • 3 cup quick-cooking oats
  • 1 cup M&Ms (red, white, and blue for patriotic version)
  • 0.5 cup chocolate chips
  • 0.5 cup mini chocolate chips

Equipment

  • 1 sheet pan

Method
 

Prepare to bake
  1. Preheat the oven to 350°F and line two baking sheets with parchment paper, leaving the parchment visible for easy cookie release.
Mix the cookie dough
  1. Beat creamy peanut butter, brown sugar, and granulated sugar together in a large bowl until combined and glossy.
  2. Add large eggs, vanilla extract, and baking soda, then mix until smooth and thick.
  3. Stir in quick-cooking oats until fully incorporated, then fold in M&Ms (red, white, and blue for patriotic version), chocolate chips, and mini chocolate chips.
Shape and bake
  1. Scoop the dough into 2-tablespoon balls and place them 2 inches apart on the prepared baking sheets.
  2. Flatten each ball slightly with your palm so the cookies bake into thick, even rounds.
  3. Bake for 10–12 minutes until edges are set but centers still look slightly underdone.
Cool and set
  1. Let the cookies cool on the baking sheet for 5 minutes until they firm up slightly.
  2. Transfer to a wire rack and cool so the centers finish setting while the edges stay golden.

Notes

Pro tip: for the thick, chewy texture, avoid overbaking—pull the cookies when the centers still look a touch underdone. Store airtight at room temperature for 4 days or in the fridge for up to 7 days; freeze baked cookies for up to 2 months. For a gluten-free swap, use certified gluten-free quick-cooking oats (the recipe will still work as written).