For the short pastry, quickly knead flour, 125 g sugar, butter in pieces and 1 egg to a smooth dough. Wrap in foil and chill for about 30 minutes.
For the sponge cake, roast breadcrumbs in a hot pan without fat until golden brown. Take out and let it cool down. Finely chop the candied orange peel. Set aside 2 tbsp. candied orange peel for sprinkling. Mix the rest with almonds and breadcrumbs.
Roll out the short pastry on some flour (approx. 32 x 39 cm) and line the greased fat pan (approx. 32 x 39 cm) with it. Prick the pastry several times with a fork.
For the biscuit, separate 8 eggs. Beat 8 egg whites and 1 pinch of salt until stiff. Mix 8 egg yolks and 250 g sugar with the whisk of the mixer until thick and creamy. Fold in the crumb mixture and beaten egg white one after the other.
Spread the mixture on the short pastry. Bake in the preheated oven (electric cooker: 180 °C/circulating air: 160 °C/gas: see manufacturer) for approx. 30 minutes.
In the meantime, heat the wine and 3 tbsp. sugar and sprinkle the still hot cake with it. Let it cool down.
Whip the cream until stiff, adding cream stiffener and vanilla sugar. Spread some cream on the cake. Put the rest of the cream in a piping bag with a large star-shaped spout and spray 24 long tuffs onto the cake. Wash and halve the grapes and decorate the slices with them. Sprinkle with the rest of the candied orange peel.