3 squares unsweetened chocolate
1 1/2 cups confectioners' sugar
2 1/2 tablespoons hot water
3 egg yolks
4 tablespoons butter

Melt chocolate in double boiler. Remove from boiling water, add sugar and water. Add egg yolks, one at a time, beating well after each addition. Add butter, a tablespoon at a time, beating thoroughly after each amount. Makes enough frosting to cover tops and sides of two 9 inch layers. Double the recipe to make enough frosting to cover tops and sides of three 10 inch layers.