Preheat oven to 350℉.

To a large bowl or electric stand mixer, add the cake mix, brown sugar, butter, peanut butter, water, and egg, and mix until well combined. Stir in the mini mu0026ms, chocolate chips, and oats.

Line a cookie sheet with parchment paper or spray with non-stick spray. Using a cookie scoop, scoop the dough and place it onto the cookie sheet, leaving 2-3 inches in between each cookie. Bake for 12-13 minutes. Let cool on the cookie pan for 2 minutes then transfer to a cooling rack. Enjoy!