Let the berries thaw at room temperature. Place them in a tall mixing bowl, sprinkle jam sugar on top and puree them with a hand blender for about 45 seconds. Fill the jam into 2 prepared twistoff jars (each containing approx. 200 ml).
Seal them and put them in cold storage. Tip: Prepare the berry jam the day before. It keeps fresh in the refrigerator for 14 days.
Mix 500 g flour, baking powder and sugar in a mixing bowl. Add the soft butter in flakes and knead everything briefly with the dough hooks of the hand mixer. Add 150 ml milk and 1 egg and knead both briefly into the dough.
Then knead everything with your hands until the dough is really smooth. But only very briefly, so that the dough doesn't get tough.
Preheat the oven: Electric cooker: 200°C/circulating air: 175°C/gas: stage 3. Lay out 2 baking trays with baking paper. Roll out the dough on some flour 1,5-2 cm thick. Cut out about 18 hearts with a heart cutter (about 7 cm Ø).
Knead the remains of the dough again and again and roll them out. Put the hearts on the trays. Whisk the egg yolk and 2 tablespoons of milk. Spread the hearts with it.
Bake the scones hearts in the oven one after the other for about 12 minutes. Take them out of the oven and let them cool down on a cake rack. Fill the quark, crème fraîche and vanillin sugar into a mixing bowl and mix them briefly with a whisk.
Dust the scones hearts with icing sugar and serve with the quark cream and berry jam.