Preheat oven to 350. Spray two 8 or 9 inch cake pans with pam. Mix up each brownie mix separately according to directions on boxes.
Bake about 25 to 30 minutes checking center of brownies to make sure they are done in the center. Remove from oven. run a knife around side of cake pan and the let cool 10 minutes. Remove brownies from pan and let cool completely.
Frosting-Melt the butter (microwave or stove top) and stir in the cocoa. Alternately add the powdered sugar and the milk, beating to a spreading consistency. Add more milk if needed. Stir vanilla extract.
Frost brownie layers like a regular layer cake all over. Then pat mini chips to the side of the cake with your hands. Enjoy with whipped cream or alone