Servings: 12 cups

2 (1 pound) boxes plus ½ cup confectioners sugar, sifted 2 (1 pound) boxes plus ½ cup confectioners sugar, sifted
1 cup cocoa powder, sifted 1 cup cocoa powder, sifted
5 sticks butter 5 sticks butter
1 ¼ cups vegetable shortening 1 ¼ cups vegetable shortening
¾ cup milk ¾ cup milk
2 teaspoons vanilla extract 2 teaspoons vanilla extract

Stir together confectioners sugar and cocoa. Set aside. In a large mixing bowl, beat butter and shortening until soft. Add the sugar/cocoa mixture in two to three increments. Add milk and vanilla and whip for 5 minutes.
Store any leftover frosting in refrigerator; rewhip when ready to use.