Melt 150 g butter. Break the rusks roughly and put them in a freezer bag. Crumble finely with a rolling pin. Add butter and mix well. Spread a thin layer of oil on the springform pan (26 cm Ø). Put the crumbs into the form and press them evenly onto the rim and base. Place the baking tin in a cool place for about 1 hour.
Wash lemon hot and rub dry. Grate half of the peel. Halve the lemon and squeeze the juice. Melt 50 g butter and let it cool down a little. Separate the eggs. Whisk egg yolks and 200 g sugar with the whisk of the hand mixer until thick and creamy. Gradually add 500 g mascarpone and quark. Stir in lemon zest, lemon juice and 50 g butter. Sift the starch on top and fold in. Beat egg white until stiff. Add 1 pinch of salt and 100 g sugar, fold in carefully. Put the mixture into the mould
Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) on the lower rack for approx. 35 minutes. Take out and cut into the edge of the cake about 2 cm deep. Let rest for about 10 minutes, then bake for another 20-25 minutes. If the cake rises too high and threatens to slip over the edge, cover the cake with aluminium foil or a cake ring. Take the cake out of the oven and let it cool down on a cake rack
Squeeze 1/2 lemon. Wash and clean the strawberries. Puree 50 g strawberries. Halve or quarter the rest depending on size. Mix 250 g mascarpone, 50 g sugar, lemon juice and vanillin sugar. Whip cream until half stiff and fold in
Remove the cake from the mould and place it on a plate. Spread the cream loosely on the cake. Swirl the strawberry puree into streaks. Sprinkle with strawberries and chill until serving
waiting time approx. 2 1/2 hours