Start by washing the apples thoroughly. Cut them in half and remove the cores. Slice each half very thinly, about 1/8-inch thick. If you want to enhance the flavor, soak the apple slices in a mixture of water and lemon juice for about 5 minutes.

In a large bowl, mix the apple slices with brown sugar and cinnamon. Let the mixture sit while you prepare the pastry.

Lightly flour a clean surface. Roll out the puff pastry sheet to flatten it a bit and make it easier to cut. Cut it into long strips, each about 2 inches wide.

On each strip of pastry, overlap the apple slices along one edge. Starting from one end of the strip, carefully roll the pastry up. Pinch the edges to seal and create a rose shape. Place these roses in a muffin tin to help them hold their shape while baking.

Preheat the oven to 375°F (190°C). Line a baking sheet with parchment paper and place the roses on it. Bake for about 25-30 minutes, or until the pastry is golden brown and flaky.

Once done, let them cool slightly. If desired, sprinkle with powdered sugar before serving.