For the short pastry, put flour and baking powder in a bowl. Spread fat in small flakes on top. Add egg yolk, sugar and a pinch of salt. Knead with the dough hooks of the hand mixer to a smooth short pastry. Wrap dough in foil and chill for 30 minutes. For the chocolate sponge cake, beat the eggs, sugar and vanilla sugar with the whisk of the hand mixer for 8-10 minutes until thick and frothy. Mix flour, cornstarch, baking powder and cocoa and fold into the egg mixture. Pour the dough onto a baking tray lined with baking paper, smooth it down and bake in a preheated oven (electric cooker: 175 ° C / gas: level 2) for 10-15 minutes.
Turn the sponge cake onto a tea towel sprinkled with sugar. Remove the baking paper immediately and let the cake cool down. Roll out the short pastry on a floured work surface to a circle (26 cm Ø) and bake in a greased springform pan or on a baking tray in a preheated oven (electric range: 175 ° C / gas: level 2) for about 20 minutes until golden brown. Take out and let cool down. For the cream, soak the gelatine in cold water. Wash and clean the strawberries and puree them with the cutting stick of the hand mixer. Mix the sugar, yoghurt and lemon juice with the strawberry puree. Squeeze the gelatine, dissolve and stir into the strawberry cream. Whip whipped cream and egg white separately until stiff. As soon as the cream starts to gel, fold in the whipped cream and beaten egg white. Spread the strawberry cream on the chocolate sponge cake. Cut the sponge cake into approx. 6 cm wide strips. Roll up a strip and place it like a snail on the middle of the shortcrust pastry base. Place the next sponge cake strip around it. Continue like this until all the strips are used up.
Whip whipped cream and egg white separately until stiff. As soon as the cream starts to gel, fold in the whipped cream and beaten egg white. Spread the strawberry cream on the chocolate sponge cake. Cut the sponge cake into approx. 6 cm wide strips. Roll up a strip and place it like a snail on the middle of the shortcrust pastry base. Place the next sponge cake strip around it. Continue like this until all the strips are used up. Place a springform ring (26 cm Ø) around the cake and put it in the fridge for 1 hour. To decorate, wash the strawberries and dab dry. Whip the cream until stiff. Remove the edge of the cake and spread the cake all around with cream. Press small dents into the cream with a spoon. Place the strawberries on the cake. Sprinkle with cocoa. Makes 16 pieces
Place a springform ring (26 cm Ø) around the cake and put it in the fridge for 1 hour. To decorate, wash the strawberries and dab dry. Whip the cream until stiff. Remove the edge of the cake and spread the cake all around with cream. Press small dents into the cream with a spoon. Place the strawberries on the cake. Sprinkle with cocoa. Makes 16 pieces
Preparation time (without waiting time) approx. 2 hours