4 tbsps butter or margarine

1/4 cup cocoa powder

1/4 cup buttermilk

1 tsp vanilla essence

2 1/4 cups sifted powdered sugar

In saucepan,combine first 3 ingredients;bring to boiling(mixture may appear slightly curdled)

Remove from heat.Stir in vanilla essence and sifted powdered sugar;

immediately pour over brownies;spread to edges.