Tip 1: Marsala is a fortified wine from western Sicily made sweet or dry. For this recipe we will use a sweet variety. If you are unable to find it you can use any dessert wine. Tip 2: Once the sugar has been added to the egg yolks it must be whisked together immediately to prevent lumps forming. Tip 3: Once the eggs are put over the double boiler, you must continuously whisk to prevent the egg yolks from turning into scrambled eggs. Tip 4: This dessert cannot been made in advance unless you freeze it. Tip 5: Instead of berries any seasonal fruit can be used.