Pour coffee into a pie dish or wide shallow bowl with 2 tablespoons of the Marsala. Combine eggs, sugar, and remaining 1/3 cup Marsala in a large double boiler only half full of simmering water or a metal bowl set on top of (but not in) a pot of simmering water. Use an electric hand mixer to beat the eggs until mixture doubles in volume and reaches 160°F on a thermometer. This process may take up to 10 minutes and several tests using an instant read thermometer.
Remove mixture from heat and allow to cool slightly. Clean and dry beaters. In another bowl, use the electric mixer to whip heavy cream to form peaks. Set aside.
Gently whisk the mascarpone cheese into egg mixture. I find it helps to break up the mascarpone into large spoonful's versus simply emptying the whole container into the egg mixture. Mascarpone with slowly melt as it's whisked in. Fold in the freshly whipped cream.
If you're using hard and crunchy ladyfingers similar of hardness to say biscotti, dunk each cookie in the coffee and arrange snuggly side by side in the bottom of the baking dish. If, however, using soft and spongy ladyfingers similar to angel food cake, arrange snuggly side by side in the bottom of the baking dish and use a pastry brush to brush the coffee mixture over each cookie.
Evenly spread half of mascarpone cream over the moistened ladyfingers. Dip or brush remaining half of ladyfingers in coffee and repeat layering with cookies and mascarpone cream.
Use a fine mesh sieve to sift a layer of cocoa over the entire top so it infuses the mascarpone cream. Wrap dish with plastic film making sure the plastic does not touch or rest upon the tiramisu. Refrigerate at least 9 hours and up to 1 day. To serve, sift another layer of cocoa over top and cut into squares. Arrange on plates with fruit, chocolate curls, or chocolate shavings if desired.