1 1/2 (1 oz.) unsweetened chocolate sq.
2 tbsp. butter
1 1/2 c. sifted confectioners sugar
1 tsp. vanilla

Melt chocolate and butter over low heat, stirring constantly. Remove from heat. Stir in sugar and vanilla until crumbly. Blend in 3 tablespoons boiling water. Add enough water (about 2 teaspoons), a teaspoon at a time, to form medium glaze of pouring consistency. Pour quickly over top of cake. Spread glaze evenly over top and sides.