1/2 cup butter, softened (you can use margarine but the flavor will not be the same)
2 2/3 cups confectioners’ sugar, sifted
1/3 cup half-and-half cream (can use unwhipped whipping cream in place of half and half) or 1/3 cup milk (can use unwhipped whipping cream in place of half and half)
1 1/2 teaspoons vanilla
CHOOSE ONE OF THE FOLLOWING
1/3 cup unsweetened cocoa powder, sifted (for light)
1/2 cup unsweetened cocoa powder, sifted (for medium)
3/4 cup unsweetened cocoa powder, sifted (for dark rich)
1 Cream the butter in a small bowl.
2 Blend in the cocoa powder (the amount desired for a light, medium or dark flavor), vanilla, confectioners sugar, alternately with the cream.
3 Beat with an electric mixer, until the desired texture is achieved.
4 **NOTE** because of the additional cocoa powder more cream may have to be added in to reach desired consistency.
More information source:www.keyingredient.com