Preheat your oven to 400°F (200°C). Place the oven rack in the center position and line two baking sheets with parchment paper.

Combine the granulated sugar, ground cinnamon, and salt in a small bowl. Stir until evenly mixed and set aside.

Sprinkle a clean, smooth surface with 2-3 tablespoons of the cinnamon sugar mixture. Unfold one sheet of puff pastry on the prepared surface and use a rolling pin to gently roll it out to a 9x12-inch rectangle.

Sprinkle 1/4 cup of the cinnamon sugar mixture evenly over the rolled-out pastry. Gently press the sugar mixture onto the dough using the rolling pin.

Starting with the shorter sides of the pastry, roll each side inward tightly toward the center until both rolls meet in the middle. Gently press the rolls together to form a log shape. Repeat this process with the second puff pastry sheet using the remaining sugar mixture.

Transfer the rolled logs to a baking sheet or plate and chill in the refrigerator for 10-15 minutes to firm them up and make slicing easier.

Using a sharp knife, slice each chilled log into 1/2-inch thick pieces. Arrange the slices cut side up on the prepared baking sheets, leaving approximately 2 inches (5 cm) between each piece as they will spread while baking.

Bake in the preheated oven for 12 minutes, or until the bottoms are golden and caramelized. Carefully flip them over and bake for another 5 minutes, or until both sides are golden brown and crispy.

Remove the palmiers from the oven and allow them to cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely. Serve and enjoy!