Made from thinly rolled puff pastry dough that’s been folded in finely ground sugar, palmiers rise into caramelized, crispy cookies. Store-bought puff pastry dough makes what is otherwise a time-consuming treat a cinch.
What to buy: Be sure to look for an all-butter puff pastry; the flavor is superior. You will find brands like Dufour in the freezer section of many specialty grocery stores, including Whole Foods. Avoid brands made with partially hydrogenated shortening.
We’ve written this recipe to accommodate puff pastry brands sold in both one and two sheets.
This pastry was featured as part of our Parisian Sweets photo gallery.
Place the puff pastry sheet(s) on the sugar mixture with one of the short ends closest to you and sprinkle the remaining sugar mixture evenly on top. If you’re using a single puff pastry sheet, roll the dough into a 1/8-inch-thick rectangle, sprinkling loose sugar from the work surface onto it as you roll. If you’re using two sheets, roll each to 1/8 inch thick (you will have two 9-inch squares), sprinkling loose sugar from the work surface onto the dough as you roll. 
If you’re using two 9-inch square sheets, fold each in half. 
Fold one half lengthwise over the other (as if closing a book). You should now have one long piece (or two pieces) of dough about 2 inches wide. Gently run the rolling pin over the top of the dough piece(s) to press the layers together. Refrigerate until firm, about 30 minutes. 
Dip the slices on both sides in the reserved ground sugar. 
Place the slices on one of the prepared baking sheets 1 1/2 inches apart; about 12 to 15 should fit. 
Bake until the sugar around the edges of the palmiers just starts to caramelize, about 8 to 10 minutes. Remove the baking sheet from the oven and flip each palmier over with a spatula. The palmiers will spread; use the spatula to push them back together, being careful not to touch the hot sugar with your fingers.
