1/2 c. butter
2 c. powdered sugar
1 1/2 tsp. vanilla
2 (1 oz.) squares unsweetened chocolate, melted & cooled
2-4 tbsp. hot water

Heat butter in saucepan until melted; stir in powdered sugar, vanilla and chocolate until blended. Stir in water, 1 tablespoon at a time, until glaze is desired consistency.