Line a baking tray (approx. 35 x 40 cm) with baking paper. Separate the eggs. Beat the egg whites, 2 tbsp. cold water and salt until stiff, adding 125 g sugar and 1 packet of vanilla sugar. Beat the egg yolks separately into the mixture. Sift the flour, starch and baking powder into it and fold in. Spread on the baking tray. Bake in a hot oven (electric range: 200 °C/circulating air: 175 °C/gas: level 3) for approx. 12 minutes
Wash and clean the strawberries and puree them with lemon juice, 50 g sugar and 1 packet of vanillin sugar, except for about 3
Take out the sponge cake and turn it over onto a tea towel sprinkled with 3 tbsp. sugar. Remove baking paper immediately. Cover the sponge cake with a damp tea towel. Let it cool down
Soak gelatine in cold water. Coarsely chop the pistachios. Mix curd cheese, pureed strawberries and pistachios. Squeeze the gelatine and dissolve over a mild heat. Stir in 2 tbsp. quark mixture, then stir into the rest of the quark mixture. Chill until it begins to gel (approx. 20 minutes). Whip cream until stiff. fold 1/2 cream into the quark mixture
Remove the upper cloth from the sponge cake. Spread the sponge cake with curd cream, leaving an approx. 1 1/2 cm wide edge all around. Roll up the sponge cake from the long side with the help of the lower cloth. Chill for about 2 hours.
Quarter the rest of the strawberries. Dust the roll with icing sugar and cut into slices. Decorate with the rest of cream, strawberries and chopped pistachios