Preheat the oven to 180°C (approximately 350°F).
Thaw the puff pastry. Roll out on a floured work surface to the size of the tart pan. Line the tart pan with the dough and cut the edge to form a crust.
Prick several times with a fork and bake for about 10 minutes.
Separate the eggs and beat the yolks with the quark, sour cream, sugar, cornstarch and orange juice into a smooth cream. Whip the egg whites until stiff and fold into the egg yolk mixture. Pour the mixture onto the crust and bake another 25 minutes.
Remove from oven and let cool. Rinse the blueberries and drain well. Evenly sprinkle the blueberries over the tart and cut into pieces Serve dusted with powdered sugar.