1/3 c. softened butter
1/8 tsp. salt
3 c. confectioners' sugar (sift if lumpy)
3 (1 oz.) squares unsweetened chocolate (melted)
1/4 c. milk
1 1/2 tsp. vanilla

Beat butter, salt and 1 cup confectioners' sugar until light and fluffy. Blend in melted chocolate. Then add rest of sugar alternately with milk and vanilla. Mix until smooth and creamy. Add more sugar to thicken or milk to thin frosting if needed for good spreading consistency.