Large eggs are labeled as such. Do not substitute extra large or jumbo. All produce should be washed well and dried before proceeding with recipes. Powder sugar should be treated differently than flour when sifting. Powder sugar must be sifted through a sieve or sifter because it can pack down or lump during shipping.
Lumpy sugar makes lumpy icing.
Spoon powdered sugar into a sifter or sieve holding it over a bowl, operate the handle of the sifter or push through the sieve with a wooden spoon, stirring if necessary, to break up any lumps. Then gently spoon it into a dry measuring cup or measuring spoon. Level off excess with a straight edge or metal spatula. Baking soda, powder, salt, cornstarch and cream of tartar should fill measuring spoon and then level off with a knife. One cube of butter is a half cup or quarter pound.