This is an OREO® cookie base with OREO® crumbs, covered in birthday cake cream cheese frosting then topped with OREO® cake ball pieces and rainbow sprinkles.
Preheat oven to 350 degrees. Use parchment paper or a silpat mat to line a baking sheet.
Cream the butter, sugar and brown sugar in a stand mixer until light and fluffy (about 2-3 minutes). Scrape the sides of the bowl to make sure all ingredients are blended.
Add in egg and vanilla and beat until combined.
Add in flour, dark cocoa, Oreo crumbs, baking soda, baking powder, and salt. Mix until all combined.
Scoop out dough and roll into balls. Scoop out a little less than 1 TBSP dough for smaller cookies (or 1/4 cup dough for BIG cookies). Place dough balls on prepared pan (12 cookies to a pan if smaller cookies) and slightly flatten with your hand to about 3/4 – 1 inch thick.
Bake for 8 minutes. Cool cookies cookie sheet for 10 minutes before removing to cooling rack. NOTE: If you decide to make the bigger cookies, you’ll need to bake them for 13-15 minutes.
While cookies are cooling, make the frosting.
Birthday Cake Cream Cheese Frosting
In stand mixer, cream butter and cream cheese for about 2-3 minutes until smooth.
Add in the birthday cake flavoring and powdered sugar and mix on high for about 3 minutes until smooth. If the frosting is too thick, add milk a teaspoon at a time to get the consistency you are looking for. If frosting is too thin, add more powdered sugar.
Put the frosting in a piping bag with a star tip OR you can put the frosting in a gallon size Ziploc bag and cut off one corner of the bag. Use the frosting bag to pipe frosting in a spiral on top of the cooled cookies. Sprinkle each cookie with sprinkles and crushed oreos