For Nuss-Eckerl, prepare a shortcrust pastry from flour, butter, powdered sugar, egg and salt.
Form into a ball, wrap in plastic wrap and let rest in the refrigerator for about 1 hour.
Preheat oven to 185 degrees top-bottom heat. Roll out the shortcrust pastry between two layers of cling film to a thickness of 3-4 mm and place on a baking tray lined with baking paper. Bake for approx. 10 min. (dough should only be baked on, should remain light in color). Allow to cool slightly and spread with the jam.
For the nut mixture, mix hazelnuts, powdered sugar, vanilla sugar and cinnamon, add egg whites and honey and mix well again. Then bring water to the boil in a saucepan and thicken the nut mixture over steam, stirring frequently.
Spread the warm nut mixture on the jam-coated shortcrust pastry and let it stand for at least 1/2 hour, then bake at approx. 175 degrees Celsius top-bottom heat for approx. 25 minutes. Cool slightly and cut into small triangles.
For the decoration, melt dark chocolate with coconut oil over steam and spread over the cookies with a small spoon.