For the shortcrust pastry, put flour, baking powder, salt, 75 g sugar, 1 egg, 1 packet vanilla sugar, butter in flakes and hazelnuts in a mixing bowl. Knead with the dough hook of the hand mixer.
Then work into a smooth dough with cool hands. Cover the dough and put it in a cool place for about 30 minutes. In the meantime, pour the peaches onto a sieve and drain well. Put the remaining eggs, remaining vanilla sugar and sugar, sour cream and sauce powder in a mixing bowl and mix well.
Cut peach halves into 4 slices each. Roll out the dough to a circle (approx. 33 cm Ø) on a floured work surface. Line a twist-off tin (29 cm Ø) with parchment paper as desired (otherwise grease or line with baking paper).
Place the shortcrust pastry exactly in it and prick several times with a fork. Spread the peaches on top and pour the custard evenly over the pastry. Bake in the preheated oven (electric: 200 °C/ gas: level 3) for 45-50 minutes on the lowest rack.
In the meantime, heat the jam in a small pot and pass it through a sieve. Take the quiche out of the oven, place it on a rack and let it cool down. Brush the peach slices with jam and dust the edge with icing sugar.
Serve decorated with mint as desired. Whipped cream tastes good with it. Makes about 12 pieces.