Thaw your puff pastry sheet and roll it into a square. Trim the edges to make it even from all the sides.
Take sugar and sprinkle generously all over the puff pastry. Be extra generous here, sugar is important so sprinkle lots.
Flip and cover the other side with sugar too. An easy way to do this is sprinkle sugar on your work surface (a little away from where your puff pastry is) and then gently lift your pastry dough and place it over that sprinkled sugar surface. You can flip the sides to see if there's enough sugar.
Now fold the pastry to mark the center, just mark it using your finger. Start folding from one side. We will do 2 folds from each side and will leave a little space in the center between the two folds in the end because ultimately we have to fold it in a log.
And then the 2nd fold, ending slightly away from the center.
Repeat the same 2 fold process from the other end, ending slightly away from the center.
And finally roll one fold on top of the other and form a log.
Trim the edges so that you can get clean pieces. Wrap in a cling sheet and refrigerate for 30 minutes or till it's firm. It's easier to cut this way!
Once the puff pastry is firm, take it out and cut into 1/2-1 centimeter pieces. The thinner you cut them the crispier the palmiers will be.
Preheat your oven to 400 F degrees. Line a baking sheet with parchment paper or silicone mat. Set aside.
Once you have cut all the palmiers, start rolling each in more sugar. Roll from both sides.
After you have rolled the palmiers, take each and shape them a little by pulling the two ends slightly away from each other. [see picture above]
Repeat the same with all the cookies and then place them on a baking sheet lined with parchment paper or silicone mat.
Bake at 400 F degrees for 15-16 minutes, flipping them once at the half way mark. Please remember to flip at half time else they won't get properly baked from both sides.
Let the palmiers cool down and then store in an airtight container.