Finely chop the pistachios and knead with the marzipan. Set aside. Mix flour and baking powder, make a depression in the middle. Add eggs, salt, sugar, vanillin sugar and orange-back and mix with part of the flour. Add 150 g fat and quark and knead everything into a smooth dough. Knead in almonds and pistachios. Roll out the dough into an oval shape, pressing a depression in the middle lengthwise.
Roll out marzipan of the same size and place on the quark dough. Form into a stollen and place on a baking tray lined with baking paper. Bake in the preheated oven (electric: 200 °C/ gas: level 3) for 10 minutes. Reduce the temperature (electric oven: 175 °C/ gas: stage 2) and bake for another 45 minutes. Melt the remaining fat and spread it on the hot stollen. Dust with icing sugar. Results in approx. 20 slices