Mix 500 g flour, 50 g sugar, vanilla sugar, yeast and 1⁄2 tsp salt. Warm up the milk. Add 50 g butter and eggs to the flour mixture. Knead with the dough hooks of the mixer for about 8 minutes to a smooth, elastic dough.
Cover and leave to rise in a warm place for about 1 hour.
Grease the box form (approx. 1 3⁄4 l capacity; 30 cm long). Mix 150 g sugar with cinnamon. Knead the dough briefly, roll out just under 1 cm on a lightly floured work surface. Spread with 100 g butter and sprinkle with cinnamon sugar.
Cut the dough into squares (à approx. 8 x 8 cm).
Stack 5-6 dough squares on top of each other and place them vertically in the mould. Repeat the process until all squares are in the mould. Cover and leave to rise in a warm place for about 30 minutes.
Preheat oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer). Bake bread in a hot oven for 30-40 minutes. Remove from the oven and leave to rest in the mould for approx. 30 minutes. Then carefully turn over and arrange.