The Italian dessert known as zabaglione, a rich concoction of whipped egg yolks, sugar and sweet wine, is a classic for a reason, but it can be heavy and too sweet and/or boozy. This five-ingredient mascarpone mousse we encountered in Milan is both lighter and simpler. Unlike zabaglione, which uses only yolks and is cooked over a double boiler, the mousse, known as crema al mascarpone, uses egg whites as well, making it airy and light. It requires no cooking and comes together in minutes. Just be sure the mascarpone is softened to cool room temperature so it combines easily with the egg yolks. A hand mixer makes easy work of whipping the egg whites, but you also could use a whisk and little elbow grease. Serve the mousse as soon as it's made, or cover and refrigerate for up to 45 minutes. A dusting of cocoa adds visual appeal as well as a hint of chocolate flavor; fresh berries or crisp cookies also are excellent. Note that the eggs are not cooked.