For large cake:
1/3 c. soft butter
3 c. confectioners' sugar, sifted
1 1/2 sq. unsweetened chocolate, melted
1 1/2 sq. semi-sweet chocolate, melted
Enough cream for correct consistency
1 1/2 tsp. vanilla
For small cake:
1/4 c. soft butter
2 c. confectioners' sugar, sifted
1 sq. unsweetened chocolate, melted
1 sq. semi-sweet chocolate, melted
Enough cream for correct consistency
1 tsp. vanilla

Blend in butter and sugar; add chocolate. Stir or beat in at low speed, cream and vanilla until smooth.