Knead flour, sugar, vanilla sugar, salt, cool fat and egg to a smooth shortcrust pastry. Wrap in foil and put in a cool place for about 1 hour. Chop the apricots very finely in a food processor or with a knife. Knead with marzipan, egg white and icing sugar and fill into a piping bag. Roll out the dough into a rectangle (25 x 40 cm) on a floured work surface. Cut into 5 cm squares.
Spray the filling as strips in the middle and fold over the ends of the dough diagonally. Whisk the egg yolk and milk and brush the croissants with it. Bake in the preheated oven (electric: 175 °C/ gas: level 2) for 15-20 minutes. After cooling down, dust with icing sugar. Heat the jam, turn the pistachios in it and press them onto the biscuits. Results in about 40 pieces