Fabulous Fudge Frosting

This Fudge Frosting is the best I have ever made. It is very, very rich. The kids regularly request it on their birthday cakes or on brownies. YUM!

Karen's Fudgy Frosting (from the back of Spartan Cocoa about 16 years ago)

1/3 Cup Butter
1/3 Cup Baking Cocoa
1 1/2 tsp vanilla extract
2 Cups powdered sugar
2 Tablespoons milk

Melt butter. Remove from heat and add cocoa. Stir until well blended. Add vanilla, powdered sugar and milk. Stir until smooth. Frosting with thicken quickly, so spread immediately. Frosts two 8" or 9" round cake pans.