Preheat the oven to 350ºF (175ºC). Line a baking sheet with parchment paper.
Roll a can of dough into a round about ⅛ inch thick. Use a 10-inch (25cm) dish or pan to make a circle outline in the dough, pressing into the dough but not cutting all the way through. Spread a layer of chocolate hazelnut spread over the dough.
Repeat with 2 more cans of dough, so you have 3 frosted layers, then stack on top of the first. Roll out the remaining can of dough and lay on top of the last frosted layer.
Using the same pan, cut the excess dough around the edges so you are left with a 10-inch round.
Place a cup or mason jar in the center of the circle, then use a sharp knife to cut the dough into 16 equal parts or “petals”, leaving the center intact.
Next, twist 2 petals away from each other, pull them out a bit past other petals and tuck them under themselves, pinching the seams. Repeat with the rest of the petals.
Brush the star bread with the beaten egg, then transfer to the prepared baking sheet.
Bake for 40 minutes, or until bread is browned and baked through.