Melt the butter. Put 24 lady fingers in a freezer bag and crumble finely with a cake roll. Mix cookie crumbs and butter. Coat the bottom of a springform pan (26 cm Ø) with oil. Spread the crumble mixture over it, press it down to a smooth base and refrigerate. Wash and clean the strawberries, except for a few small ones for decoration.
Soak gelatine in cold water. Cut 6 sponge fingers into small pieces. Mix mascarpone, quark, sugar and 1 packet of vanilla sugar. Squeeze the gelatine, dissolve and stir in 2-3 tablespoons of quark mixture. Stir into the remaining mixture. Chill until the mixture begins to gel. Whip the cream until stiff, adding 1 sachet of vanillin sugar. Fold cream and biscuit pieces into the gelatinising mixture. Place the strawberries on the cake base with the tip pointing upwards, carefully spread the cream on top and smooth it down. Lightly tap the springform pan several times on the table top so that the cream is distributed between the strawberries. Chill the cake for 2-3 hours. Remove the cake from the springform pan and place on a cake platter.
Fold cream and biscuit pieces into the gelatinising mixture. Place the strawberries on the cake base with the tip pointing upwards, carefully spread the cream on top and smooth it down. Lightly tap the springform pan several times on the table top so that the cream is distributed between the strawberries. Chill the cake for 2-3 hours. Remove the cake from the springform pan and place on a cake platter. Cut 14 lady fingers in half and place them around the edge of the cake, press lightly. Dust the cake surface with cocoa. Halve the remaining strawberries and decorate the cake with them