Chocolate Frosting

1 stick butter
1/3 C cocoa powder
1/c half and half
4C confectioners' sugar
1 tsp. vanilla
Combine butter, cocoa and half and half in a medium saucepan over medium heat;heat to a gentle boil. Cook,stirring until mixture is dark and shiny, about 3 minutes. Remove pan from heat; stir in confectioners sugar and vanilla;beat with an electric mixer on low speed until smooth and thick.