Beat the egg whites and the other 1½ tablespoon sugar till they form peaks. Transfer to a bowl.
Beat the egg yolks with 1½ tablespoon sugar until fluffy. Add the mascarpone and beat on a low speed until well incorporated.
Gently incorporate the whites into the mascarpone mixture.
Mix the coffee and the Marsala together. Dip the savoiardi in the coffee and Marsala mix one at a time, make sure they absorb some liquid but are not saturated.
Arrange half the biscuits in the bottom of a dish and cover with the Mascarpone mixture. Form a second layer with the remaining biscuits and cover with the Mascarpone.
Allow to sit at least 2 hours in the fridge before serving. Dust with cocoa before serving.