Defrost the slices of dough. Mix sugar and cinnamon. Melt butter at a mild heat. Roll out each slice to a square (approx. 22 x 22 cm) on a little flour, brush with 1/2 butter, sprinkle 1/2 cinnamon sugar on top
Roll up firmly from both sides towards the centre. Spread with the rest of the butter and sprinkle with the rest of the cinnamon-sugar. Cut the rolls into 20 slices each, place them with enough space on trays covered with baking paper, sprinkle with sugar crystals. Bake in a hot oven (electric cooker: 200 °C/circulating air: 175 °C/gas: level 3) for about 15 minutes. Cooling down