ready in 30 min.
Preheat an oven to 400ºF / 200ºF. Line a baking sheet with parchment paper.
In a small bowl, combine sugar, cinnamon, and melted butter, stirring until it forms a paste.
Roll the pufff pastry into a large rectangle, about 15-inches by 12-inches. Using a pastry brush or spatula, spread the cinnamon sugar paste in a thin, even layer over the dough. Starting at the long ends of the rectangle, loosely roll each side inward until they meet in the middle. Brush the pastry with egg wash, to hold the pastry together.
Slice the pastry crosswise into 1/4-inch palmiers – they will look like butterflies. Arrange them on prepared baking sheet. Bake for 12 to 15 minutes, or until they puff and turn golden brown. Transfer to a wire rack and serve warm or at room temperature.