Thaw puff pastry according to package instructions.
Preheat oven to 375 Fahrenheit. Line two baking sheets with parchment paper.
In a small bowl, beat the egg and water. Set aside.
Lightly flour your surface. Unfold one thawed puff pastry sheet and lay it flat. Roll it out a few times length and width-wise until the seams are blended.
Use an offset spatula to spread the Nutella evenly on the puff pastry sheet. Leave about a 1/2 inch border around the edges.
Sprinkle lightly with finely chopped nuts or fruit, if using.
Place the second sheet of puff pastry on top of the first sheet. Gently press the edges to seal them.
Use a sharp knife or pizza cutter to cut the pastry into 1 inch wide strips. Cut the strips in half, if desired.*
Pick the strip up and twist the ends in opposite directions until strip twists. Place twists on baking sheet.
Brush the twists with the egg wash. Sprinkle generously with coarse sugar.
Bake 15-20 minutes until twists have are puffed, flaky and golden brown.
Remove from the oven and allow to cool on the baking sheet for at least 5 minutes. Enjoy warm!