3/4 c. cocoa
1/2 c. butter (1 stick)
1/2 c. evaporated milk
4 c. confectioners' sugar
1 tsp. vanilla

Mix cocoa and sugar. Cream butter and sugar mixture. Add 1/2 the milk and vanilla, cream. Add remaining milk and beat until spreading consistency. Additional milk may be added a few drops at a time if needed.