"Light and Luscious Chocolate Desserts" is a new brochure from Hershey's Cocoa with tips on reducing calories, cholesterol and fat in your favorite dessert recipes. Included are recipes for Chocolate Ricotta Cheesecake, Silky Cocoa Creme, Frozen Chocolate-Cherry Yogurt Cups, Chocolate Cupcakes and Hot Cocoa with Cinnamon. For a copy, send a stamped, self-addressed, business-size envelope to: Light and Luscious, 40 West 57th St., Suite 1400, New York, N.Y. 10019.