Chocolate Buttercream Icing
1 pound (4 sticks) unsalted butter, softened
2 1/2 cups confectioner's sugar
12 ounces semi-sweet chocolate, melted and cooled
2 teaspoons pure vanilla extract
2 tablespoons heavy cream
Combine the butter and powdered sugar in the bowl of a stand mixer fitted with the paddle attachment (or use a hand mixer) and beat until light and fluffy. Add melted chocolate and mix on low speed just until combined. Add vanilla and cream and beat until combined. Use frosting on any 8" or 9" cake.