In a shallow dish, combine the cooled brewed coffee and coffee liqueur, if using. Set aside.

In a large mixing bowl, whip the heavy cream until soft peaks form. Gradually add the granulated sugar and vanilla extract, continuing to whip until stiff peaks form.

Gently fold the mascarpone cheese into the whipped cream until well combined and smooth.

Quickly dip each ladyfinger into the coffee mixture, ensuring they are soaked but not soggy. Lay half of the dipped ladyfingers in a single layer at the bottom of a 9x9-inch dish.

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

Repeat the process 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 overnight for best results.

Before serving, dust the top with cocoa powder and garnish with grated dark chocolate.