Preheat oven to 350 degrees and line cupcake tin with paper cupcake liners.
Mix brownie mix according to package directions. With the Pillsbury brand brownie mix, blend together brownie mix, vegetable oil, water, and eggs. Stir together just until incorporated. Set aside.
In another bowl combine the vanilla cake mix, water, vegetable oil, and eggs. Mix on low speed until blended. Then stir in your food coloring.
Fill cupcake liners 1/3 of the way with brownie batter. I was able to fill about 22 cupcakes.
Then carefully spoon orange cake batter on top of the brownie batter to fill muffin cups 2/3 full. (I had leftover cake batter) You can make regular cupcakes with the extra cake batter if you want.
Bake for about 15 to 20 minutes. Just until golden and the tops spring back when lightly pressed. Remove from pan and cool completely.
In a large mixing bowl cream together the butter, shortening and vanilla. Then add in milk and powdered sugar 1 cup at a time. Mix together until light and fluffy. Pipe onto cooled cupcakes and add sprinkles to the top.