Start by grating the apples using the coarser side of the grater.
Transfer to a medium bowl, add the ground cinnamon, the sugar and mix everything very well until fully combined.
Next, cut the puff pastry into 3 equal strips and separate them.
Then, divide the apple we prepared earlier into three equal portions and add each portion to the center of each pastry strip using two tablespoons.
Then seal each strip by bringing the ends together.
Transfer to a baking sheet lined with parchment paper and make shallow cuts on each pastry using a pastry cutter.
Finally, brush one beaten egg over everything.
Take to a preheated oven at 180° C (350° F) and bake for 20 minutes.
After this time has passed, finish by sprinkling powdered sugar over everything.
Serve.