In warm milk, mix yeast with sugar (6 g.) And leave in a warm place for 10-15 minutes. Put the amount of yeast according to the instructions on the package. Milk can also be replaced with water.
Melt the butter 30g. and mix it with a whisk with egg yolk. Add flour, salt (0.25 tsp) and milk with yeast. Stir and knead the dough.
Put the dough in a bowl greased with vegetable oil and leave in a warm place for 1.5 hours. At this time, make the filling. To do this, melt the butter and mix it with sugar and cinnamon.
Roll out the dough 1 cm thick. Lubricate 2/3 of the filling.
Roll the dough into a roll. Place the seam down and squeeze a little, making the roll more flat. Cut the roll along, not cutting to the end by 1-2 cm. Interlace the two halves of the roll. Then form a vicious circle. Top with the remaining stuffing.
Bake at 200 degrees for 20-25 minutes. Before serving, you can sprinkle baking powdered sugar.