Roll up the puff pastry and place a plate on a baking sheet lined with baking paper. Peel, core and grate the apples. Mix with cinnamon and sugar and spread on the puff pastry, leaving a margin of about 1 cm.
Whisk the egg and coat the edge of the puff pastry with it. Place the second plate and press it down a little. Bake at around 180 ° C for 20-30 minutes. Tastes super delicious with vanilla ice cream.