Prepare the workspace by tearing a 12-inch length of parchment paper. Next, lay the pastry on the parchment and cut an 8-inch length (so you’re working with an 8-inch-by-12-inch sheet of pastry). Rewrap the remaining dough, and return it to the refrigerator or freezer for another use.

Sprinkle about 1/4 cup sugar over the top of the puff pastry.

Using a rolling pin, roll the sugar into the puff-pastry sheet. Pick it up, flip it over, and do the same on the new side, again with about 1/4 cup sugar.

Arrange the sheet of pastry vertically, with the 8-inch side closest to you. Beginning at the bottom edge, fold over 2 inches of pastry once, then again. Repeat with the top edge so that both edges, doubly folded, meet in the middle, with a small gap in between.

Gently compress the folded dough with a rolling pin. Brush one side with an egg wash, then fold the other side over, the folded edges atop one another like a book. (The egg wash binds the two sides together.)

Again use the rolling pin to press the dough gently, then wrap the dough log in plastic wrap and chill it for 20 minutes. Meanwhile, preheat the oven to 375 degrees and line a baking sheet with parchment paper.

After 20 minutes, remove the dough from the refrigerator. Score the roll every 1/4 inch . . .

. . . then slice it into cookies.

Place the cookies on the parchment-lined baking pan, leaving plenty of space between them (three across by four high).

Put the palmiers in the oven.

When the bottoms of the cookies begin to brown (at about 10 minutes), pull the baking sheet from oven and quickly flip the cookies, then return them to the oven for another 8 minutes or so . . .

. . . until the tops caramelize.

Remove the cookies from the oven, and let them cool before storing them in an airtight container. Merci, Piper!