Soak the gelatin sheets in water for a few minutes, then squeeze out the excess water and melt them in a small saucepan with 1 tablespoon of heavy cream.

To prepare the tiramisu, start with the eggs (make sure they are very fresh): separate the egg whites from the yolks, making sure there is no yolk in the whites. Beat the yolks with an electric mixer, gradually adding the sugar. Once the mixture is pale and fluffy, with the mixer still running, add the mascarpone a little at a time. When all the mascarpone is incorporated, you should have a thick, smooth cream.

Clean the beaters thoroughly and beat the egg whites until stiff peaks form. The whites are ready when the mixture doesn't move if you turn the bowl upside down.

Add a spoonful of the beaten egg whites to the yolk and sugar mixture and mix vigorously with a spatula to loosen the mixture. Then gently fold in the remaining egg whites a little at a time, mixing carefully from bottom to top.

Whip the heavy cream until stiff peaks form. Add the melted gelatin, then gently fold the whipped cream into the mascarpone mixture.