Switch on the oven to approx. 180 ° C (hot air). Roll out the puff pastry and cut into approx. 5 x 5 cm squares or the size you want. I also tried something and this is the size I liked best because it is nice and bite-sized.
Then put some Nutella on each square, fold it up and press the edges with a fork if necessary. Spread the squares on a baking sheet and brush with a beaten egg. Bake for about 15-20 minutes until they are nice and brown.