Also called sugar apple, the sweetsop is the egg-shaped fruit of a small tropical-American tree. It has a thick, coarse yellow-green (sometimes purple-tinged) skin and yellow flesh with dark seeds. The very sweet, custardlike flesh is divided into segments like a citrus fruit. The sweetsop is often mistaken for the cherimoya (or custard apple), to which it is related. It's grown in Florida and California and is usually available from midsummer to midwinter only in the locales where it's grown. After the skin and seeds are removed, sweetsops are usually eaten raw. They're often used in desserts.