Espresso Frosting Recipe

Beat egg yolk with mixer until thick and lemon colored; set aside. In a medium saucepan combine sugar, water, and espresso powder; bring to a boil, stirring until all is dissolved. Cook over medium high heat. Stir constantly, until thickened to soft-ball candy stage. Quickly pour the hot mixture in a steady stream over yolks, beating constantly on high speed. Continue beating till mixture is thick and smooth. Cool 15 minutes.

Meanwhile, beat the butter until light and fluffy. Beat the butter, 1 tablespoon at time, into cool yolk mixture. Cover and chill for 30 minutes or until stiff enough to spread. Stir semisweet chocolate pieces into 1/2 cup of the buttercream. Stir chocolate mixture into rest of buttercream. Spread on cooled cake.