Line a springform pan (26 cm Ø) at the bottom with baking paper. Separate the eggs. Beat the egg whites and 3 tbsp. cold water until stiff, add 75 g sugar and vanillin sugar. Fold in the egg yolks one by one. Sift flour, starch and baking powder on top and fold in. Brush into the mould. Bake in the preheated oven (electric cooker: 200 °C / convection oven: 175 °C / gas: level 3) for 18-20 minutes. Cooling down
Soak 4 and 6 gelatine leaves separately in cold water. Warm the nectar. Squeeze out 4 gelatine leaves, dissolve in it and cool down. Keep cold until the nectar begins to gel (takes 1-2 hours)
Mix sour cream, 100 g sugar and champagne. Squeeze 6 sheets of gelatine and dissolve over a mild heat. Stir in 5 tablespoons of sour cream, then stir into the rest of the cream. Chill until it begins to gel. Whip cream until stiff. Fold into the cream. Then fold in the nectar as "streaks
Cut the biscuit so that the top is thin and the bottom is thick. Crumble the thin base and meringue. Place the edge of the mould around the thick base. Spread cream on top. Spread the crumbs slightly dome-like on top. Chill for 4-5 hours. Dust with icing sugar and decorate