Grease one half of a fat pan (approx. 32 x 39 cm) and dust with flour. Cut off the middle with a rail made of aluminium foil folded several times. Separate the eggs. Beat the egg whites and 1 pinch of salt until stiff, adding 50 g sugar and 1 vanillin sugar. Beat the egg yolks separately. Sift flour, starch and baking powder on top and fold in
Spread the sponge cake on half of the fat pan. Bake in the preheated oven (electric cooker: 200 °C/circulating air: 175 °C/gas: level 3) for approx. 12 minutes. Let them cool down
Wash, clean and halve the strawberries. Put the sponge cake on 1 plate. Wrap baking frame or a rim of multiple folded aluminium foil (approx. 6 cm high) around it. Mix mascarpone, quark, 50 g sugar and 2 vanilla sugars briefly. Whip 100 g cream until stiff and fold in. Spread on the sponge cake and cover with strawberries. Chill for about 1 1/2 hours.
Mix casting powder and 2 teaspoons of sugar. Stir in 1/4 l cold water, bring to the boil while stirring. Cool down briefly. Spread the mixture from the middle out with a tablespoon on the strawberries. Chill for about 30 minutes.
Whip 400 g cream until stiff, adding cream firming agent and 1 tsp. sugar. Pour into a piping bag (large perforated spout). Spray the cream tuffs close together on the strawberries. Chill for about 30 minutes. Sprinkle the slices thickly with cocoa shortly before serving
An all-round success
Instead of slices you can also bake a cake in the springform pan (28 cm Ø)