For the beugel with nut filling, mix the eggs with salt, granulated sugar, vanilla sugar and the grated lemon zest. Add the yeast and 2/3 of the milk and mix well.
Cut the cold butter into pieces and add. Also add the flour and knead with the dough hooks until a firm dough is formed.
If necessary, add the remaining milk. Knead the dough for about 5 minutes until it comes away from the bottom.
Knead into a dough ball on a floured work surface, cover with plastic wrap and let rest for about 15 minutes.
For the filling, whisk together the grated nuts, bread crumbs, granulated sugar, vanilla sugar, cinnamon and gingerbread spice.
Add milk, apricot jam and rum and mix well. If the filling is too soft, add a little more milk before processing to prevent it from oozing.
Divide the dough into pieces weighing about 50 g and shape into balls with your hands. Roll out flat, oval, hand-size on a floured work surface with a pasta walker.
Fill with filling, press dough down, re-roll and shape into croissants. Brush with beaten egg and bake the balls with nut filling at 175 °C (hot air) for approx. 15 minutes.