Knead a shortcrust pastry from the ingredients for the dough. Put in the fridge for 30 minutes. Then roll out into a rectangle the size of 35 x 45 cm.
For the filling, mix the ground hazelnuts with the other ingredients to form a smooth mass. Spread thinly on the dough.
Roll up the dough from the longer side and place it on a greased baking sheet as a wreath (possibly just a semicircle).
Whisk the egg yolk with the milk and brush the wreath with it. Cut the wreath about 1/2 cm deep at regular intervals. Bake at 180 degrees for about 30 - 35 minutes.