1 1/2 sticks butter, softened 1 cup cocoa powder, such as Hershey's
1/2 cup milk (I have even used nonfat) 2 tsp vanilla
2 tsp espresso powder 1/2 tsp salt
1 box confectioners sugar
In a standing mixer, mix butter, cocoa, espresso powder, sugar and salt. I used to sift the sugar and cocoa together, but no longer do that. Start out slow as the cocoa powder tends to fly everywhere, but everything will start to incorporate. After a few minutes, put the mixer on a medium speed (I use 4 on my Kitchenaid) and add the milk gradually. You may need a little more, but be careful...rule of thumb is better to have a stiffer frosting than to add too much milk and have it start to slide down the sides of your cake. Bon appetit!
P.S. I made a frosting a little too thin the other day, and after you frost a cake, there's no saving it, except to bring the frosting back up the sides and immediately refrigerate. The only problem is, I personally don't like cold cake, so if you don't either, err on the side of too little liquid.