Jelly rolls, also known as Swiss rolls or jelly cakes, consist of a sponge cake coiled around a jelly filling. They are usually sliced crosswise to reveal an attractive spiral pattern and are occasionally used as the decorative exterior for a charlotte (a molded cake filled with custard or fruit or Bavarian cream). The spiral cross-sections of jelly roll line a handsome exterior for this gelatin-set mousse. The earliest reference to them has been found in several cookbooks published immediately after the American Civil War, but they are thought to have arisen at the same time the genoise sponge cake appeared, in mid-nineteenth-century France. Common fillings include currant jelly, pastry cream, apricot preserve, and raspberry jam. Baking pans designed for cooking the thin sheets of batter used for jelly rolls have flat bottoms and one-inch-high straight sides. Called “jelly-roll pans” by consumers, they have become standard baking equipment in commercial kitchens, where they are referred to simply as “sheet pans.” “Jelly roll” and “honey pot” were popular slang euphemisms for female genitalia at the turn of the twentieth century, and it is likely that the famous jazz pianist Jelly Roll Morton acquired his nickname from playing in bordellos.