Prepare the Mascarpone Cream
In a medium bowl, whisk the egg yolks and granulated sugar until pale and creamy, about 2–3 minutes.
Add the mascarpone cheese to the mixture and beat until smooth and creamy.
In a separate bowl, whip the cold heavy cream to stiff peaks using an electric mixer.
Gently fold the whipped cream into the mascarpone mixture until fully combined, being careful not to deflate the cream.
Prepare the Coffee Soak
In a shallow dish, combine the cooled coffee and coffee liqueur (if using).
Dip the Ladyfingers
Quickly dip each ladyfinger into the coffee mixture, ensuring they are soaked but not soggy.
Assemble the Tiramisu
Arrange a layer of soaked ladyfingers at the bottom of an 8×8-inch (20×20 cm) dish.
Spread half of the mascarpone cream evenly over the ladyfingers.
Repeat with another layer of dipped ladyfingers and top with the remaining mascarpone cream.
Finish with Cocoa
Sift a generous layer of unsweetened cocoa powder over the top.
Chill and Serve
Cover the dish and refrigerate for at least 4 hours or overnight for best results.
Before serving, dust with additional cocoa powder or garnish with dark chocolate shavings.