Cinnamon Palmiers

Line 2 large rimmed baking sheets with parchment paper.

On a lightly floured surface, unfold 1 puff pastry sheet. Whisk egg in a small bowl until frothy. Stir together sugar and cinnamon in a separate small bowl until combined. Brush pastry sheet with some of the egg, and sprinkle with half of the sugar mixture. Unfold remaining pastry sheet, and place on top. Brush top with egg, and sprinkle with remaining sugar mixture.

Using a floured rolling pin, roll out to a 14- x 10 1/2-inch rectangle. Starting on 1 long side, roll the pastry into a tight spiral, stopping at the middle of the pastry. Starting on the other long side, roll the pastry into a tight spiral, stopping at the middle of the pastry. Brush with egg where the two spirals meet, and gently press together. Using a serrated knife, cut into 1/2-inch-thick slices. Place 2 inches apart on prepared baking sheets. Refrigerate, uncovered, until chilled, about 15 minutes. Preheat oven to 400°F.

Bake in preheated oven, 1 baking sheet at a time, until golden brown and puffed, 15 to 18 minutes per batch. Let cool completely, about 15 minutes. Serve.