1 (1 lb.) box confectioners' powdered sugar
1 (8 oz.) carton sour cream
1 tsp. vanilla or lemon flavoring
1/4 stick butter
2 tsp. milk

Sift confectioners' sugar, mixed with all remaining ingredients together along with confectioners' sugar. Smooth over cakes, cupcakes, etc. Refrigerate any remaining icing for later use.