First, mix sugar with cinnamon.
Roll out the puff pastry, sprinkle it densely with the sugar-cinnamon mixture and cut it in half.
Roll up each piece separately, and cut into slices about 1.5 cm thick.
Place on a baking tray covered with baking paper and bake at 180 °C in the preheated oven for approx. 15-20 minutes.