Cut butter into pieces. Separate egg. Knead flour, 50 g sugar, vanillin sugar, egg yolk and butter first with the dough hooks of the hand mixer, then with your hands to a smooth dough. Wrap dough in cling film and chill for approx. 30 minutes. Lightly roast almonds and hazelnuts in a large pan without fat, remove.
Cut the cherries into small pieces. Beat both egg whites until stiff, while letting 75 g sugar trickle in. Continue beating until the sugar has dissolved. Fold in nuts and cherries. Knead the dough again briefly on a floured work surface, then roll out approx. 2 mm thin. Cut out circles (6 cm Ø). Knead dough again and cut out circles again. Put 1 teaspoon of nut filling in the middle of each circle, fold up the edges of the dough on 3 sides and press firmly against the filling. Place the cookies on 2 baking trays lined with baking paper and refrigerate for another 20 minutes, then bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) one after the other for about 15 minutes until golden brown.
Knead the dough again briefly on a floured work surface, then roll out approx. 2 mm thin. Cut out circles (6 cm Ø). Knead dough again and cut out circles again. Put 1 teaspoon of nut filling in the middle of each circle, fold up the edges of the dough on 3 sides and press firmly against the filling. Place the cookies on 2 baking trays lined with baking paper and refrigerate for another 20 minutes, then bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) one after the other for about 15 minutes until golden brown. Let the cookies cool down on a cake rack