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Monster Cookies

Monster cookies are thick, chewy peanut butter cookies loaded with M&Ms, chocolate chips, and visible oats. Bake until golden at the edges with soft, slightly underdone centers, then cool so they firm up.
Prep Time 15 minutes
Cook Time 12 minutes
Total Time 27 minutes
Servings: 24 servings
Course: Dessert
Cuisine: American
Calories: 290

Ingredients
  

Peanut butter
  • 1.5 cup creamy peanut butter
Sugar
  • 1 cup brown sugar, packed
  • 0.5 cup granulated sugar
Eggs
  • 3 large eggs
Flavorings
  • 2 tsp vanilla extract
Baking soda
  • 1 tsp baking soda
Oats
  • 3 cup quick-cooking oats
Candy and chips
  • 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 and preheat
  1. Preheat the oven to 350°F and line two baking sheets with parchment paper, keeping the paper flat so the cookies bake evenly (visual cue: parchment fully covers the sheet).
Mix the dough
  1. Beat the creamy peanut butter, brown sugar, and granulated sugar together in a large bowl until combined and glossy (visual cue: no dry sugar pockets remain).
Add wet ingredients
  1. Add the large eggs, vanilla extract, and baking soda, then mix until smooth (visual cue: the mixture looks uniform and thick).
Add oats and mix-ins
  1. Stir in the quick-cooking oats until fully incorporated (visual cue: oats are evenly distributed and the dough looks thicker).
Fold in color and chocolate
  1. Fold in the M&Ms (red, white, and blue for patriotic version), chocolate chips, and mini chocolate chips so they are visible throughout the dough (visual cue: colorful bits and chips are dotted in every scoop).
Shape the cookies
  1. Scoop dough into 2-tablespoon balls and place them 2 inches apart on the prepared baking sheets, flattening slightly with your palm (visual cue: discs are about the same thickness).
Bake
  1. Bake for 10–12 minutes until the edges are set but the centers still look slightly underdone (visual cue: centers appear soft and not fully browned).
Cool and finish
  1. Let the cookies cool on the baking sheet for 5 minutes before transferring to a wire rack so they firm up as they cool (visual cue: cookies hold their shape when gently nudged).

Notes

For the thickest, chewiest texture, keep the dough portions uniform at about 2-tablespoon balls and flatten only slightly—over-flattening can spread. Store in an airtight container at room temperature for up to 4 days. Freeze baked cookies up to 2 months. Dietary swap: use dairy-free chocolate chips if you want a dairy-free version while keeping the same baking soda and oat structure.