Pre-heat oven to 350°.Place jar of Nutella in fridge for at least 3-4 hours or until very cold and firm.Grease and flour a 6 medium size muffin tin.Thaw puff pastry if frozen, unroll and using a rolling pin, roll to even it out but do not make it too thin, cut into 6 squares, make sure you leave a strip for cut outs or decorator ropes.Place a big scoop of Nutella in the middle** of each square and starting from the opposite ends bring up the corners to meet, do this again with the remaining corners (see photos) and squeeze to close. Decorate with twisted strips of pastry or cut outs. Place in prepared muffin tin and sprinkle with sugar, bake for approximately 20 minutes. Let cool enough to handle, dust with powdered sugar and serve. Enjoy!
** You could also place spoonfuls of Nutella on a parchment paper lined cookie sheet and then freeze them for an hour then place one in the middle of each square.