Whip 6 egg yolks with tablespoons of sugar on a double boiler till the eggs turn pale yellow. Add 1/4 cup of marsala wine while still whipping the zabaglione till thickens again. Remove from stove top and let cool to room temperature. Fold in mascarpone cheese. Chill in refrigerator while making whipped cream. 2 cups of heavy whipping cream and 1/4 cup of sugar and whip till peaks. Fold in zabaglione in whipped cream about a 1/4 cup at a time. When all is folded in chill for 1 hour.
Make 16 ounces of espresso. Add 2 ounces of dark rum and 5 tablespoons of sugar.
Need 9 x9 deep dish pan or plastic storage container. Dip one side of savoiardi and line the pan side by side with savoiardi. Fill 1/3 of cream mixture on top of savoiardi and smooth out, repeat steps 2 more times. Smooth out the top cream and sprinkle shaved or grated dark chocolate on top of cream. Cover with plastic wrap oe storage lid and chill for 4 hours.