Dissolve the yeast in the lukewarm milk. Knead the yeast milk with flour, ground walnuts, butter, eggs, sugar and salt in a bowl with a dough hook to form a dough that should no longer stick. Knead in more flour if necessary.
Then let the dough rise in a warm place for about an hour.
Knead the dough well again and roll out into a flat rectangle.
Chop and mix the walnuts and cranberries for the filling.
Melt the butter in a saucepan and add the walnut-cranberry mixture. Sprinkle with the sugar and heat briefly while stirring.
Distribute this mixture evenly on the yeast square. Leave a few centimeters at the edges.
Roll up into a long roll, braid into a braid and let rise for another 10 minutes.
Bake at 170 degrees for 10 minutes. Then brush with egg yolk and sprinkle sugar on top. Bake for another 15 minutes at 170 degrees top / bottom heat.