Heat the milk in a saucepan and let the butter melt in it. Let the milk-butter mixture cool down until it is about lukewarm. Mix the flour with the yeast and gradually fold in the other ingredients including the lukewarm butter-milk mixture and knead with a mixer on the highest setting for about 5 minutes to form a smooth dough. Put the dough in a large bowl and cover and let rise in a warm place until the volume has doubled. I preheat the oven to 50 ° C and cover the bowl with the dough for 30-40 minutes. In this way the dough has reliably grown to double the amount after the time has elapsed.
In the meantime, for the filling, melt the butter and mix well with the sugar and cinnamon and set aside.
Take the dough bowl out of the oven, preheat the oven to 160 ° C fan oven. Line two baking sheets with parchment paper. Roll out the dough on a floured surface into a 25 x 70 cm rectangle. Evenly distribute the filling with the help of a brush so that some of the filling remains and roll up the rectangle. Now cut about 12 trapezoids.
Place the trapezoid with the wider area on baking paper and use a wooden spoon to press a recess up to the worktop so that the typical Franzbrötchen shape is created. This can still look a bit awkward before the baking process. When baking, however, the dough rises nicely and the result is unique.
Brush the Franzbrötchen a little more with the filling, put in the oven and bake for 15-20 minutes. Make sure that the dough does not get too dark, otherwise the Franzbrötchen will dry out.