1) Clean and cut the berries and divide into the four glasses.
2) Place the double boiler or pot on a burner and fill to a point 1 inch below where the bottom of the bowl will rest. The simmering water must not touch the bottom of the bowl. Turn on the heat and bring the water to a simmer.
3) In a stainless steel bowl mix the sugar into the egg yolks and whisk together immediately, using a wire whisk or a hand mixer. Once the mixture has been whisked to a foamy consistency add the Marsala and whisk together and place over the double boiler or a pot of simmering water. Whisking continuously in a figure 8 motion, until the mixture has gone pale and quadrupled in volume. Pour over the fruit and garnish with the mint sprigs and serve.
