This M&M COOKIE CAKE has a sugar cookie dough filled with M&M's and some chocolate buttercream frosting on top and is the perfect dessert to enjoy with friends and family.
Preheat oven to 350 degrees F and grease a 9 inch pie dish.
Beat butter for 2 minutes until smooth. Mix in sugar until fluffy. Add in the egg, yolk, and vanilla until smooth, creamy, and light in color.
Add the flour, cornstarch, baking powder, baking soda, and salt and mix until combined.
Mix in the m&m's by hand (they're break if you use the mixer) until evenly distributed.
Spread dough in the greased pie dish. Bake for 23-26 minutes. Cool completely before removing from pie dish and frosting.
Beat butter and cocoa powder together. Mix in the powdered sugar and vanilla. Add the milk as needed to get desired consistency.
Place frosting in a piping bag with an M1 tip and decorate the cookie cake. Immediately add the M&M's and sprinkles.