Heat 400 g cream (do not boil!). Break the chocolate into pieces and melt in it while stirring. Let it cool down. Chill overnight
Line the bottom of a springform pan (26 cm Ø) with baking paper. Separate the eggs. Beat the egg white and salt until stiff, adding sugar. Beat in the egg yolks one by one. Sift flour, starch and baking powder into the mixture and fold in. Brush into the mould. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/gas: level 2) for approx. 25 minutes. Cooling down
Cut the cake base into an egg shape on two sides and halve it horizontally. Finely crumble the sponge cake remains. Whip the truffle cream until stiff and cut in half. Fold the sponge crumbs under one half with a dough scraper. Spread the lower cake base with it and place the 2nd cake base on top. Spread the rest of the truffle cream on the cake. Chill for about 1 hour.
Coarsely grate the marzipan and knead with icing sugar. Roll out to a circle (approx. 28 cm Ø) between foils. Cut out an egg the size of the cake and lay it on the cake. Cut out flowers from the remaining marzipan. Decorate the edge of the cake with them. Whip 125 g cream until stiff, allowing vanilla sugar to trickle in. Decorate the cake with cream tuffs etc. and dust with icing sugar