Brew and cool the coffee. Make strong espresso or coffee and let it cool to room temperature. Stir in the liqueur and vanilla, if using. Pour into a shallow dish for easy dipping.

Set up a bain-marie. Bring an inch of water to a gentle simmer in a pot. Place a heatproof bowl on top so the bottom doesn’t touch the water.

Whisk the yolks. Add egg yolks, a pinch of salt, and half the sugar to the bowl. Whisk constantly over the steam for 5–7 minutes until the mixture is pale, thick, and increased in volume. Remove from heat and let it cool for a few minutes.

Beat the mascarpone. In a separate bowl, whisk the mascarpone briefly until smooth. Don’t overbeat—just loosen it up.

Combine the two. Gently fold the mascarpone into the yolk mixture in two additions until smooth and creamy.

Whip the cream. In a clean bowl, whip the heavy cream with the remaining sugar to soft-medium peaks. It should hold shape but still look silky.

Fold it all together. Fold the whipped cream into the mascarpone mixture in two or three additions. Use gentle strokes to keep the mixture airy.

Dip the ladyfingers. Quickly dip each ladyfinger into the coffee—about 1 second per side. They should be soaked but not soggy.

Build the first layer. Arrange a tight layer of dipped ladyfingers in a 9x9-inch dish (or similar). Trim pieces if needed to fit.

Add the cream. Spread half the cream mixture over the ladyfingers. Smooth the top with a spatula.

Repeat. Add a second layer of dipped ladyfingers, then the remaining cream. Smooth the top again.

Chill. Cover and refrigerate for at least 6 hours, ideally overnight. This helps the flavors meld and the layers set.

Finish and serve. Just before serving, sift a generous layer of unsweetened cocoa powder over the top. Add chocolate shavings if you like. Slice and serve cold.