This is what you need:
hard Ladyfingers (NOT the soft ones! I usually buy a big package and use 2 layers)
4 super fresh eggs
500g mascarpone (the Italian one, or the one from Trader Joe's)
espresso (I usually use VERY strong coffee)
Spread out the ladyfingers in one or two layers and soak with the coffee
(make sure they're not getting too wet).
Put the mascarpone, sugar and egg yolks in a bowl.
Mix together until smooth and creamy.
Beat the egg whites until stiff.
Carefully spoon the stiff egg whites under the cream.
Stop as soon as it is blended nicely.
Put a first layer of soaked ladyfingers on the bottom of a deep dish.
Spoon a first layer of cream on top of it.
Add a second layer of soaked ladyfingers...
... and a second layer of mascarpone.
When you're done, cover with plastic wrap and chill overnight.
Shortly before serving, shake cocoa powder on top of the chilled cream...
until it is completely covered.
And then there's only one thing left -