1-Brew strong coffee or espresso and mix in 1 tablespoon of rum if using. Pour the mixture into a wide, shallow bowl and let cool to room temperature.

2-Separate the egg yolks and whites. Beat the egg whites with half of the sugar until stiff peaks form; set aside.

3-In a separate bowl, beat the egg yolks with remaining sugar until pale and fluffy. Add mascarpone, the remaining rum, vanilla extract, and a pinch of salt; mix gently until smooth.

4-Carefully fold half of the beaten egg whites into the mascarpone mixture to lighten it, then fold in the remaining whites until fully combined without streaks.

5-Spread a thin layer of the mascarpone cream on the bottom of a 9×9 inch or similar-sized dish. Quickly dip each ladyfinger (1–2 seconds) in the coffee mixture do not soak, to prevent sogginess and arrange a single layer over the cream.

6-Spread half the remaining mascarpone cream evenly over the ladyfingers.

7-Repeat with another layer of coffee-dipped ladyfingers and then top with the remaining mascarpone cream.

8-Refrigerate uncovered for at least 4 hours to allow flavors to meld and the dessert to set, preferably overnight. If stored longer than 4 hours, cover loosely with plastic wrap without pressing it onto the cream.

9-Just before serving, dust generously with cocoa powder.