Cooks Note: If there are any lumps in the confectioners' sugar the frosting will be lumpy unless the sugar is sifted or pulverized in a food processor until smooth. Use only a good quality pure vanilla extract. Cheap vanilla or imitation will leave more of an alcohol taste since this is not going to be baked or cooked. Using vanilla that has been on the shelf for several years may produce a bland taste or require more vanilla to be used.

If you have concerns about using raw egg whites, see Pasteurization of Eggs or use a store-bought pasteurized egg product.