1. Whip the heavy cream at medium speed until well-fluffed, about 5 minutes. Transfer the whipped cream to a bowl and keep it in the refrigerator. In the mixer bowl, add the mascarpone cheese, sugar, and vanilla, and beat until creamy, about 3 minutes.
2. Remove from the mixer and, using a spatula, fold 1/3 of the whipped cream into the mixture. Fold gently with circular motions to maintain the air in the whipped cream. Repeat with another 1/3 of the whipped cream, and once incorporated, add the remaining amount. Pour the espresso coffee into a bowl and add the coffee liqueur. Stir well.
3. Dip the ladyfingers into the coffee mixture and arrange them in the serving dish for the tiramisu. Alternate layers of cream and coffee-dipped ladyfingers until all ingredients are used. Place the dessert in the refrigerator for at least 2 hours or overnight. Before serving, dust with cocoa powder.
