Spread 3-4 sheets of plastic wrap to create a rectangle about 11.81x15.75 inches (30x40 cm).
Dip the ladyfingers in coffee on both sides (they break easily) and arrange them on the plastic wrap in two adjacent rows of 10 ladyfingers each, for a total of 20. Arrange them tightly. Let them sit at room temperature for about 45 minutes until they are softened and can be folded without breaking.
In a stand mixer, whip the mascarpone cheese with sugar, cream, and vanilla pudding powder for about 2 minutes until it forms a stable whipped cream. Cover and refrigerate until needed.
Spread most of the whipped cream over the ladyfingers (save 4 tablespoons for decoration). Make the whipped cream higher in the center. Use the plastic wrap to fold both edges upward to form a round cake with the ladyfingers wrapped around the mascarpone cream. Sift the cacao powder over the ladyfingers. Pipe the remaining whipped cream in the center, using a star nozzle if desired. Chill for about an hour in the refrigerator before serving.