Separate eggs. Beat the egg whites and 4 tablespoons of cold water until stiff, adding salt, 150 g sugar and vanillin sugar. Stir in the egg yolks one by one. Mix flour, cornstarch and baking powder and sieve onto the egg mixture. Carefully fold everything in. Put the sponge mixture on a baking tray lined with baking paper and smooth it down. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for 12-15 minutes.
Turn onto a tea towel sprinkled with 3 tablespoons of sugar, remove paper immediately. Roll up the sponge cake from the long side using the tea towel. Cover with another damp tea towel and allow to cool. Soak gelatine in cold water. Put 3-4 strawberries aside for decoration. Wash, clean and quarter the strawberries. Puree 150 g strawberries and lime juice. Mix the puree, 50 g sugar and quark together. Squeeze the gelatine and dissolve over a mild heat. Remove 2-3 tablespoons of quark cream and mix with the gelatine. Stir the gelatine mixture into the remaining quark. Fold in strawberries. Put them in a cool place.
Mix the puree, 50 g sugar and quark together. Squeeze the gelatine and dissolve over a mild heat. Remove 2-3 tablespoons of quark cream and mix with the gelatine. Stir the gelatine mixture into the remaining quark. Fold in strawberries. Put them in a cool place. Whip cream until stiff. As soon as the cream starts to gel, fold in the cream. Carefully roll up the roll and spread the cream on top, leaving a 1 1/2 cm margin all around. Roll up the sponge cake from the long side. Chill for at least 4 hours. Wash, clean and slice the remaining strawberries. Cut the sponge roll into pieces and decorate with strawberry slices
Whip cream until stiff. As soon as the cream starts to gel, fold in the cream. Carefully roll up the roll and spread the cream on top, leaving a 1 1/2 cm margin all around. Roll up the sponge cake from the long side. Chill for at least 4 hours. Wash, clean and slice the remaining strawberries. Cut the sponge roll into pieces and decorate with strawberry slices