Special equipment: 6 highball glasses
In a medium bowl whisk the espresso powder, water and whiskey together until the granules dissolve. Set aside.
In a medium bowl, lightly blend the mascarpone cheese with vanilla extract.
In a separate bowl, whisk the heavy cream while slowly adding the sugar. Beat until soft peaks form when the whisk is raised from the whipped cream. Fold the mascarpone into the whipped cream mixture and set aside.
To assemble, arrange 6 glasses on a work surface and build each glass individually. Soak a few ladyfingers in the espresso mixture for a few seconds, then arrange them vertically inside the glass, lining the sides. Repeat until the circumference of the glass is covered with the soaked ladyfingers. Scoop or pipe the whipped cream on top of the ladyfingers, then sprinkle with a layer of chocolate shavings. Top with a thin layer of soaked and crushed ladyfingers, then with an equal scoop of whipped cream and again sprinkle with chocolate shavings. Repeat with the remaining 5 glasses and refrigerate for at least 2 hours or overnight before serving.