1 cup confectioners sugar
2 tablespoons shortening
2 tablespoons fresh coffee (I use decaf)
3 tablespoons unsweetened cocoa powder
1 teaspoon vanilla extract
Put all ingredients in a bowl and beat together using a hand mixer until it's smooth and light. You can mix it manually if you wish but the hand mixer makes it easier and whips it up nicely. If it comes out to stiff add a small amount more coffee but do so in real small increments.
This will cover a single layer box mix cake. It's also great for doughnuts. You can double or triple the recipe as you need.