Preheat oven to 350 F. Whisk together flour, cocoa powder, baking powder and salt in a mixing bowl and set aside
Mix together brown sugar, white sugar, and softened butter in a stand mixer for about 5 minutes. Add egg and vanilla extract and mix for another minute.
With the stand mixer on, slowly add flour mixture until fully mixed together. Add in chocolate chips
Place cookie dough in a lightly greased 13x9 baking dish, and flatten out until evenly spread. Add min m&m’s on top. Place in oven for 18-23 minutes.
Let cool one a cookie rack, and store in an airtight container, enjoY!