This is my go-to recipe:
Recipe for Tiramisu
(adapted from Gourmet)
480ml of espresso sweetened with 1 tbsp sugar
113g caster sugar
3 tablespoons Kahlua
4 large egg yolks
80 ml dry Marsala
500g (1 big tub) mascarpone cheese, room temperature
300ml chilled heavy whipping cream (at least 35% fat)
36 savoiardi (crisp Italian ladyfingers)
Unsweetened cocoa powder for dusting
Combine egg yolks, Marsala, and 1/2 cup sugar in a metal bowl. Set mixture over a saucepan of barely simmering water and beat using a whisk or handheld electric mixer until tripled in volume (7 to 9) minutes. Mixture should look thick, creamy and pale. Remove bowl from heat. Gently beat in mascarpone until just combined.
Beat whipping cream until it holds stiff peaks.
Fold mascarpone mixture into whipped cream gently but thoroughly.
Dipping both sides of each ladyfinger into espresso, line bottom of a 13- by 9- by 3-inch baking pan or dish with ladyfingers, trimming to fit if necessary. Each ladyfinger should not be dipped into the espresso for more than 1 second for each side. The dipped ladyfinger should feel wet and moist on its outside but still have a firm core. Brush ladyfingers with half the Kahlua. Spread half of mascarpone filling on top and dust lightly with cocoa powder.
Repeat with a second layer of ladyfingers.
Chill, covered, for at least 6 hours before serving.