In a large mixing bowl, combine mascarpone, ladyfingers, vanilla extract and sugar. Blend well using a spatula. Then, set aside.
In another large mixing bowl, pour in heavy whipping cream. Using a hand or stand mixer, whip until stiff peaks forms.
Gently combine whipped cream and mascarpone batter very well.
In a large shallow bowl, prepare the coffee. Dip the ladyfingers one by one (don't soak) and assemble the first layer in a 3-quart baking dish or cake pan. Spread the custard evenly at least a quarter thick over the first layer. Repeat the process until you reach the top of the pan.
Cover with lid or plastic wrap. Refrigerate at least 4-6.
Sprinkle the powdered cocoa or shredded chocolate on top using a sifter. Serve.