icing is a sugar-based medium for enhancing and decorating many types of cake and other sweetmeats. Although a plain cake should still taste superb, it is often the icing on the cake that identifies it. Would we recognize an American carrot cake, the Dobos torta from Hungary, or a traditional British Christmas cake without their decorative layer of sugar?
Our love of sweetness may not be innate, but it is certainly ancient: honey brushed over an oven-hot cake was recommended in the fifth century by Apicius. Until smoothly ground icing sugar, or confectioner’s sugar, was produced by commercial refineries in the nineteenth century, it was necessary to crush lump sugar in a mortar, then brush or shake the powdery grains through a fine-meshed cloth or sieve two or three times. See sugar and sugar refining.