For the Nutella tiramisu, beat the eggs with the sugar until foamy. Add the whipped cream and mix with a mixer. Add the mascarpone and gently stir it in.
Heat the milk and melt a small spoonful of Nutella in it. Dip the biscuits in it and layer them in a baking dish.
Stir the remaining Nutella into the milk. Spread one third of the mascarpone cream on the biscuits. Put a layer of the milk-Nutella mixture on top.
Continue layering in this order until all the ingredients are used up. Finish with a layer of the mascarpone cream. Sprinkle the Nutella tiramisu with cocoa powder.