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Monster Cookies

Monster cookies are thick, chewy peanut butter cookies loaded with M&Ms, chocolate chips, and visible oats in every bite. Baked until golden at the edges with soft centers, they’re an easy no-flour–style cookie recipe that still delivers classic chewy texture.
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Prep Time 15 minutes
Cook Time 12 minutes
Total Time 27 minutes
Servings: 24 servings
Course: Dessert
Cuisine: American
Calories: 240
Ingredients Equipment Method Notes

Ingredients
  

Peanut butter cookies 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
 

Prep and preheat
  1. Preheat the oven to 350°F and line two baking sheets with parchment paper.
  2. Beat the peanut butter, brown sugar, and granulated sugar together in a large bowl until combined.
Mix the dough
  1. Add the eggs, vanilla, and baking soda, then mix until smooth.
  2. Stir in the quick-cooking oats until fully incorporated, then fold in the M&Ms and chocolate chips.
Scoop and bake
  1. Scoop the dough into 2-tablespoon balls and place them 2 inches apart on the prepared baking sheets, flattening slightly with your palm.
  2. Bake for 10–12 minutes at 350°F until the edges are set but the centers still look slightly underdone.
Cool
  1. Let the cookies cool on the baking sheet for 5 minutes, then transfer to a wire rack so they firm up as they cool.

Notes

For the thick, chewy texture, measure oats accurately and don’t overbake—pull the cookies when the centers still look a touch underdone. Store airtight at room temperature up to 4 days or refrigerate up to 1 week; freeze baked cookies up to 2 months. For a gluten-free swap, confirm your quick-cooking oats are certified gluten-free (the rest of the recipe is naturally flourless).