Heat oven to 400° F. Adjust rack to middle position.
Sprinkle 1 tablespoon of sugar over the work surface. Unfold 1 sheet of the pastry and place it on the sugar. Roll it to an even thickness. Sprinkle it with 2 tablespoons of the sugar. Starting at one short side of the rectangle, roll the pastry toward the center of the sheet, stopping at the middle. Repeat with the opposite short end, so the rolls meet. Trim the ends with a knife. Cut into 1/2-inch-thick slices and place flat on a baking sheet lined with parchment paper, spacing them 1 inch apart. Sprinkle with 1 more tablespoon of the sugar.
Bake until golden and puffed, 20 to 23 minutes. Let cool for 5 minutes. Transfer to a wire rack.
Repeat with the remaining ingredients. Serve hot or at room temperature.
In Advance: Palmiers are best the day they're made, and you can bake them hours before the party.