Prep the coffee: Make a strong cup of espresso and let it cool to room temperature. If you’re using alcohol, stir in Marsala or coffee liqueur now and let it mingle.

Make the mascarpone cream: In a large bowl, whisk the egg yolks with half the sugar (about 1/4 cup) until pale and thick, 3–4 minutes. Add the mascarpone and vanilla, and beat until smooth and glossy.

Whip the cream: In another bowl, whip the heavy cream with the remaining sugar to soft peaks. If you like a sturdier layer, whip a bit longer to medium peaks.

Fold together: Gently fold the whipped cream into the mascarpone mixture in two additions until just combined and airy. A few light folds are better than heavy mixing to keep it fluffy.

Dip the ladyfingers: Quickly dip each ladyfinger into the cooled coffee for 1–2 seconds—just long enough to soak through but not so long they fall apart. Arrange a single layer of soaked fingers in your dish.

Layer and chill: Spread half of the mascarpone cream over the first layer. Dust with cocoa powder. Add a second layer of soaked fingers, then the remaining mascarpone cream. Lightly dust with cocoa again. Cover and refrigerate for at least 4 hours, ideally 6–12 hours, or overnight.

Finish and serve: Just before serving, dust generously with cocoa and, if you like, shave a bit of dark chocolate on top for a glossy finish. The dessert should be set, with the layers revealing themselves when you cut into it.