In a small bowl, combine the sugar with cinnamon together. Divide roughly into 3 parts: 2 very large and 1 very small.
Sprinkle the first large portion of cinnamon sugar on the counter or on a rolling mat (roughly in the size of your puff pastry sheet). Place puff pastry sheet on top.
Sprinkle the puff pastry with the second large portion of cinnamon sugar. Slightly roll it out to a rectangle (to thin out the pastry and so that the cinnamon sugar can stick to the pastry).
Roll up the longer side of the dough in towards the middle, now roll up the other side in towards the middle (see photos).
Use a sharp knife to cut the log into about ½-inch (1 cm) slices.
Dip each side of the cookie into the reserved cinnamon sugar mixture (third part).
Transfer the cookies to a parchment paper lined sheet pan, at least 1.5-inch (4 cm) apart to allow for the cookies to expand. Press the cookies lightly so they are of even thickness.
Preheat the oven to 400°F (200°C). Put the sheet pan with the cookies in the fridge while the oven is warming up.
Bake the cookies for 10 minutes, then flip them over and bake for a further 5-6 minutes or until golden in color. Towards the end of the baking time, keep an eye on the cookies, they can turn from golden brown to burnt very easily. When they´re golden, they´re done! Every oven bakes differently so baking time may vary. Let the cookies cool on the baking sheet.
Enjoy!