Go Back

Monster Cookies

Monster cookies are thick, chewy peanut butter no-flour cookies with oats visible in every bite and M&Ms in every color. Baked until golden at the edges with soft, slightly underdone centers for a bakery-style texture.
Print Recipe Pin Recipe
Prep Time 15 minutes
Cook Time 12 minutes
Total Time 27 minutes
Servings: 24 servings
Course: Dessert
Cuisine: American
Calories: 290
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

  • 2 sheet pan

Method
 

Prep and preheat
  1. Preheat oven to 350°F and line two baking sheets with parchment paper. Make sure the sheets are ready so the dough can be scooped right after mixing.
Make the dough
  1. Beat peanut butter, brown sugar, and granulated sugar together in a large bowl until combined. The mixture should look glossy and evenly streak-free.
  2. Add eggs, vanilla, and baking soda and mix until smooth. Scrape down as needed so no dry spots remain.
  3. Stir in oats until fully incorporated, then fold in M&Ms and chocolate chips. You should see oats throughout and have colorful mix-ins evenly distributed.
Scoop and bake
  1. Scoop dough into 2-tablespoon balls and place 2 inches apart on prepared baking sheets, flattening slightly with your palm. Keep the size consistent so they bake evenly.
  2. Bake for 10–12 minutes until edges are set but centers still look slightly underdone. Look for golden edges with a softer middle that will finish setting as they cool.
Cool
  1. Let cool on the baking sheet for 5 minutes before transferring to a wire rack. The cookies firm up as they cool.

Notes

For the thick, chewy texture, avoid overbaking—pull the cookies when the edges are set and the centers still look a touch soft. Store airtight at room temperature for up to 4 days or in the fridge for up to 7 days; freeze baked cookies up to 2 months. For a gluten-free option, confirm your oats are certified gluten-free, keeping everything else the same.