In a medium saucepan, whisk together the egg yolks and granulated sugar until well combined.

Stir in the milk and cook over medium heat, stirring continuously, until the mixture thickens. Remove from heat and let it cool slightly.

Once cooled, whisk in the mascarpone cheese until the mixture is smooth and creamy.

In a separate bowl, whip the heavy cream until stiff peaks form.

Fold the whipped cream into the mascarpone mixture gently until no streaks remain.

In a shallow dish, combine the cooled espresso and coffee liqueur (if using).

Quickly dip the ladyfinger cookies into the espresso mixture one at a time, ensuring they are soaked but not soggy.

Layer the soaked ladyfingers in a serving dish.

Spread half of the mascarpone mixture over the ladyfingers, smoothing it out evenly.

Repeat with another layer of dipped ladyfingers followed by the remaining mascarpone mixture.

Cover the dish with plastic wrap and refrigerate for at least 4 hours, or preferably overnight, to let the flavors meld.

Before serving, dust the top generously with cocoa powder for that classic finish.

Serve chilled, cut into squares for individual servings.