Soak the gelatin in water for 5 minutes.
Warm the orange juice and lemon juice and 1 tablespoon of strawberry syrup (from canned strawberries).
Drain the gelatin well and dissolve the gelatin in the warmed juice mixture while removed from the heat. Be careful that lumps do not form.
Let the mixture cool until lukewarm.
Beat the whipping cream with the vanilla sugar until stiff.
Mix the quark with the yogurt and sugar and then fold in the whipped cream.
Mix in the drained strawberries and then the fresh strawberries. Mix with electric mixer until smooth.
Once smooth, add the juice and gelatin mixture and mix well.
Grease a large round spring form pan and pour the quark mixture in.
Lay ladyfingers on top till covered.
Let the cake cool and stiffen in the refrigerator for 12 hours.
Loosen the sides of the cake with a thin knife and turn the cake over (ladyfingers on the bottom) onto a large serving platter. Remove the spring form pan sides.
If desired, place more fresh strawberries on top of the cake.