Set the "savoiardi" biscuits on glass rectangular container in 2 layer. After laying the first layer pour the cold coffee you previously made, then set the second layer and pour the rest of the coffee so to cover all biscuits.
on 2 different bowls separate the eggs yalks from the white. Add the sugar to the yalks and beat them up. Then add the "mascarpone" cheese and continue to beat until it becomes homogeneous.
Beat the white of the eggs until it becomes a tough consitency (if you put upside down, it doesn't fall). Then add this foam to the rest of composition (eggs yalks, sugar and mascarpone), stirring gently to let everything become a soft cream.
Pour the cream over the biscuits in the container and expand it using a spoon to make smooth. Finally put the cocoa powder on top, just a subtle layer.
Put in the fridge for at least 2 hours (even 1 day is fine), and serve cold accompanied by a sweet wine (passito or malvasia).