ZABAGLIONE [zah-bahl-YOH-nay] is an ethereal dessert made by whisking together egg yolks, wine (traditionally marsala) and sugar. This beating is done over simmering water so that the egg yolks cook as they thicken into a light, foamy custard. Traditional zabaglione must be made just before serving. The warm froth can be served either as a dessert by itself or as a sauce over cake, fruit, ice cream or pastry. In France it is called sabayon or sabayon sauce.