For the dough, put flour, hazelnuts, sugar, salt, vanillin sugar, vanilla pulp, butter in flakes and egg in a mixing bowl. Knead with the dough hook of the hand mixer to a smooth dough. Then knead again briefly with your hands. Wrap dough in foil and refrigerate for 30 minutes. In the meantime, lightly toast the hazelnut flakes in a pan without fat. Remove from the pan and set aside.
Roll out the dough on a floured work surface (approx. 0.5 cm thick). Cut out fir trees of different sizes and place them on 3 baking trays lined with baking paper. Bake one after the other in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for about 11 minutes. Remove from the oven, place on a rack and allow to cool. Spread the cookies thinly with slightly warmed jelly. Sprinkle with the roasted hazelnut leaves and dust with icing sugar
Waiting time approx. 30 minutes