Chocolate Frosting

1/2 cup unsalted butter at room temperature
3 cups powdered sugar
3 tablespoons cocoa powder
4 tablespoons heavy cream
1 teaspoon vanilla

In a work bowl with an electric mixer, cream the butter. Sift the sugar and cocoa powder together and gradually add to the butter, beating well after each addition. Add the cream and vanilla and beat until well blended and fluffy.