For the pastry, knead all the ingredients together to make a smooth dough, adding a little cold water if necessary.
Shape into a ball, wrap in cling film and chill for approx. 30 minutes.
Preheat the oven to 180 °C, gas 4. Grease the pan.
Roll out the dough into a rectangle and place in the tray. Prick a few times with a fork and bake for 10 minutes.
Remove from the oven and leave to cool.
For the topping, drain the cherries well. Mix loosely with 1 tbsp cornflour, the lemon juice and 2 tbsp icing sugar.
Mix the cream cheese with the quark, eggs, remaining cornflour, lemon zest, vanilla and remaining icing sugar until smooth.
Pour half of the cream cheese mix onto the cake base and smooth it out.
Spread the cherries on top and cover with the remaining cream cheese mix.
For the crumble, rub all the ingredients together with your fingertips until crumbly and sprinkle on top.
Bake for 45 minutes until golden and set. Leave to cool.
Dust with icing sugar and cut into pieces before serving.
Garnish with mint if desired.