On the kitchen counter or table, sprinkle half of the sugar and place the puff pastry. Mix the grated lemon rind with the remaining sugar and a little cinnamon if desired, spread the puff pastry out onto baking paper sheet, and gently press with a rolling pin.
Roll up the puff pastry from one end into a roll up to the middle of the sheet. Then, roll the other end in the same manner, until the two rolls meet in the middle. Place the puff pastries in the freezer for 15-20 minutes.
With a sharp knife, cut the roll into individual biscuits and arrange them on a tray with baking paper. Coat them with a little butter and put them to bake in a preheated 356°F (180 °C) oven.