A recipe for making icings and fillings for cakes boiled icing – One cup of sugar, one-third cup of boiling water, white of one egg beaten stiff. Pour water on sugar until dissolved, heat slowly to boiling point without stirring; boil until syrup will thread when dropped from tip of spoon; as soon as it threads, pour slowly over beaten white, then beat with heavy wire spoon until of proper consistency to spread. Flavor.