To prepare the dough, mix the yeast and sugar with the lukewarm milk and let it sit for a few minutes while the yeast bubbles. Add the egg yolk, the melted butter, the flour and the salt, then knead the dough and shape into a ball. Place the dough in a large, greased bowl. Cover and place in a warm space and let rise until doubled in size (about 1 hour).
Preheat oven to 200°C/395°F.
Combine all the ingredients for the filling and set aside.
After an hour take the dough and divide in to 8 equal parts. On a well floured surface, roll out each dough ball to a 5" circle. With a brush spread the filling mixture on the dough, covering all of the surface in a thin layer. Roll into a log and cut lengthways into half. Now take the 2 parts and twist together and form into a round. Make sure you reveal the cut side up. Repeat with all dough balls. Transfer to a baking tray lined with baking paper. Cover with a cloth and let rise for another 30 minutes.
Brush with the remaining cinnamon-butter mix and sprinkle with sugar. I used a mixture of brown sugar and some crushed walnuts as a topping. You could however just use plain sugar if you like.
Bake at 200°C/395°F for around 5-7 minutes. Reduce the temperature to 175°C/345°F and bake for another 10-12 minutes or till nicely browned. Dust with powdered sugar and serve with a chilled glass of milk or some hot coffee or tea.
Recipe by Box of Spice at https://boxofspice.com/2013/12/mini-cinnamon-wreaths/