Preheat oven to 375°. Spray a cookie sheet with non-stick cooking spray or line it with parchment paper or a silicone baking mat.

Place cookie dough in a large bowl and then mix in the peanut butter. Add chocolate chips, M&Ms, and oats and mix well.

Use a cookie scoop to drop tablespoon-sized balls of cookie dough on the prepared cookie sheet. Bake for 10-12 minutes or until the edges begin to turn a light golden brown. Cool for about 3-4 minutes on the baking sheet before transferring to a wire rack to cool completely.