1. Whip the heavy cream on medium speed until it is nicely fluffy, about 5 minutes. Place the whipped cream in a bowl and keep it in the fridge.
In the mixer bowl, add the mascarpone cheese, sugar, and vanilla, and beat until creamy, about 3 minutes.
Remove from the mixer and, using a spatula, gently fold in 1/3 of the whipped cream into the mixture. Use circular motions to avoid deflating the air from the whipped cream. Repeat with another 1/3 of the whipped cream, and once incorporated, add the rest.
2. Pour the espresso coffee into a bowl and add the coffee liqueur. Stir well.
Quickly dip the ladyfingers into the coffee mixture and arrange them in a rectangular baking dish measuring 20x24cm.
3. Spread half of the cream mixture over the ladyfingers, then place another layer of coffee-soaked ladyfingers on top. Spread the remaining cream evenly over the top. Place the dessert in the refrigerator for at least 2 hours or overnight. Before serving, dust generously with cocoa powder.