Line a baking tray (approx. 35 x 40 cm) with baking paper. Separate the eggs. Beat the egg whites, 4 tbsp. cold water and salt until stiff, adding 100 g sugar and vanillin sugar. Beat the egg yolks separately into the mixture. Sift flour, starch and baking powder into the mixture and fold in. Spread on the baking tray. Bake in the preheated oven (electric cooker: 200 °C/circulating air: 175 °C/gas: level 3) for about 10 minutes. Turn out onto a damp tea towel. Remove paper immediately. Stir jam until smooth and spread on the hot sponge cake. Allow to cool down
Soak the gelatine in cold water. Mix 600 g quark, 75 g sugar, lemon peel and lemon juice. Squeeze the gelatine, dissolve over a mild heat. Stir in 3 tbsp. quark mixture, then stir into the rest of the mixture. Whip 200 g cream until stiff. Fold into the quark. Spread the sponge cake with it. If necessary, cut in half crosswise and refrigerate briefly so that the cream becomes a little firmer. Cut crosswise into 6 strips (approx. 6 cm wide). Roll up 1 strip spirally and place in the middle of a cake plate. Wrap the remaining strips spirally. Wrap a cake ring around it. Chill for at least 7 hours.
Whip 100 g cream until stiff. 200 g quark and 1 go. Mix tbsp. sugar. Fold in cream. Spread the cake thinly with the cream. Wash and clean the strawberries and cut them into thin slices. Place the strawberries on the cake and decorate with balm.