Mix the flour, sugar, lemon zest and a pinch of salt in a small bowl. Cut in the butter and mix with a fork or pastry mixer. Add the egg yolk and 3 tsp of cold water until the dough comes together into a loose clump. Transfer to a lightly floured surface and knead until you have a smooth ball. Put the dough in a plastic bag and chill in the fridge for 30 minutes.
Preheat the oven to 375 degrees F and grease a 9 inch tart pan. Lightly dust your work surface with flour again and roll the dough out slightly larger than the pan. Lightly flour the top of the dough, fold in half, and place it into the pan. Line the pan neatly and trim the edges with a knife. Pierce the bottom of the dough with a fork many times. Cover with a piece of parchment paper and fill with uncooked beans or rice to weigh it down. Bake for 15 minutes, then remove from the oven, remove the beans and parchment and allow to cool. Turn the oven down to 325 degrees F.
In a large bowl using a hand held mixer or in a kitchen mixer with the paddle attachment mix the quark, sugar, egg, vanilla extract and flour together until smooth.
Spread the blackberry jam or jelly evenly over the bottom of the dough. Spoon the cream evenly over the jelly and spread out to smooth the surface.
Rinse and drain the blackberries. Place each blackberry stem side down in a circular pattern, filling the entire bottom. Sprinkle 1 tbsp of sugar and the toasted almonds over the top of the blackberries.
Bake for 45 minutes or until the edges of the tart are golden. Serve the tart warm or at room temperature.
This is a versatile tart and can be made with blueberries, strawberries, peaches or made the original way with pears.