Zabaglione

6 servings. Put the egg yolks and the sugar in the heavy bottomed top of a double-boiler. Whip them with a whisk or electric mixer until they are pale yellow and creamy. Bring the water in the double boiler to the barest simmer. Assemble the boiler. Add the Marsala to the egg mixture and continue beating. The mixture should begin to foam, then swell into a light, soft mass. It is ready when soft mounds form. Spoon into goblets and serve immediately.