1 lb. unsifted powdered sugar
1/2 c. dry cocoa
1/4 tsp. salt
1 tsp. vanilla
7 tbsp. boiling water
6 tbsp. soft butter

Mix powdered sugar, cocoa and salt thoroughly, so no lumps of cocoa can be seen. Add vanilla and boiling water. Stir smooth. Add soft, not melted, butter and stir or beat until smooth, just stiff enough to spread. The frosting may seem too thin at first, but it stiffens as it cools. (If it should get too thick while spreading, stir in a few drops of hot water.)

Yields enough to cover two (8 or 9-inch) layers generously.