Also known as elephant ears, these glistening, caramelized cookies have a satisfying crunch.
Prepare the Puff Pastry.
Sprinkle work surface with the sugar. Place the puff pastry on top and roll to a rectangle 8 by 26 inches and approximately 1/8 inch thick, continually sprinkling with additional sugar to prevent the dough from sticking.
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. Slice crosswise into 3/8-inch slices. Roll over each palmier with a rolling pin to lightly flatten, and sprinkle the center of each with more sugar. Place palmiers 2 inches apart on water-sprayed baking sheets. Freeze for at least 1 hour.
Preheat oven to 450 degrees. Bake palmiers 4 to 6 minutes, until golden on the underside. Flip with a spatula, pressing down to flatten if palmiers seem to be unrolling. Bake 2 to 4 minutes more, watching carefully, until golden and crisp. Transfer to a cooling rack and cool completely.
The sugar softens the dough, so be sure to work quickly but carefully while rolling, forming, and slicing your palmiers.