Preheat oven to 425 degrees. Line 2 baking sheets with parchment paper.
In a small bowl, combine 1/2 cup sugar and 2 teaspoons cinnamon, set aside.
Spread 1 1/2 cups sugar on a flat work surface to roll out dough. Lay one sheet of puff pastry (keep the second sheet in fridge for now) on top of sugar and roll into a rectangle about 10 x15-inches, continually sprinkling with sugar to prevent sticking as you roll out the dough.
Working quickly but gently, roll each long end to the center of the pastry, making sure to roll tightly and evenly. Freeze rolled log for 20 minutes, until very firm but not frozen. Repeat steps with second pastry.
Slice first pastry log crosswise into 3/8-inch slices. Roll over each palmier with a rolling pin to lightly flatten (you could also use the palm of your hand) and sprinkle the center of each with cinnamon sugar. Place palmiers 2 inches apart on prepared baking sheets.
Bake palmiers for 6 to 8 minutes, until golden on the underside. Flip with a spatula, pressing down to flatten if palmiers seem to be unrolling. Sprinkle with more cinnamon sugar and bake 2 to 4 minutes more, watching carefully, until golden and crisp. Transfer to wire racks to cool, then store in an airtight container. Repeats steps for second log.