ORIGINAL RECIPE
1/2 cup butter
3 T. milk
2 T. cocoa
1 1/2 cups powdered sugar
1 t. vanilla

Try Hershey Cocoa Hot Fudge Frosting
That's the one I use, if you like a lot of frosting.

1/2 cup butter 3 T. milk 2 T. cocoa 1 1/2 cups powdered sugar 1 t. vanilla

Melt butter, milk,and cocoa, in heavy saucepan, stirring well to mix.
Add powdered sugar and vanilla.
Mix and beat with hand mixer.
Beat for 5 minutes.
Pour over warm cake.