01 - Preheat the oven to 400°F. Line two baking sheets with parchment paper.
02 - In a small bowl, thoroughly mix the granulated sugar, ground cinnamon, and salt.
03 - Sprinkle half of the cinnamon sugar mixture evenly over the work surface. Lay the puff pastry sheet on top.
04 - Sprinkle the remaining cinnamon sugar evenly over the pastry. Gently roll with a rolling pin into a 10x12 inch rectangle, pressing the cinnamon sugar into the dough.
05 - Starting from one long edge, tightly roll the pastry towards the center. Repeat from the opposite edge so the two rolls meet in the middle, forming a double spiral.
06 - Using a sharp knife, slice the roll crosswise into 1/2 inch slices, yielding approximately 24 pieces.
07 - Place the slices cut side up on the prepared baking sheets spaced well apart. Lightly sprinkle with extra granulated sugar.
08 - Bake for 8 to 10 minutes, then carefully flip each slice and bake for another 7 to 8 minutes until golden and caramelized.
09 - Allow palmiers to cool on the baking sheets for 5 minutes before transferring to a wire rack to cool completely.