Grease a baking tray (approx. 35 x 40 cm) and dust with flour. Separate the eggs. Beat the egg whites, 4 tbsp. cold water and 1 pinch of salt until stiff, while pouring in 175 g sugar and vanilla sugar. Beat the egg yolks one after the other.
Mix flour, starch and baking powder, sieve onto the egg foam mixture and fold in with the nuts.
Spread the sponge cake on the baking tray. Bake in the preheated oven (electric cooker: 175 °C/circulating air: 150 °C/gas: level 2) for approx. 20 minutes. Let them cool down.
Mix mascarpone, low-fat curd, espresso and 150 g sugar with the whisk of the hand mixer (see tip). Sprinkle the sponge cake with Amaretto. Spread the mascarpone cream on the sponge cake and refrigerate for approx. 1 hour.
Dust with cocoa shortly before serving.