Roll the dough into a large rectangle. Spread hazelnut spread in a thin, even layer on the dough, leaving a ¼-inch border around the edges. Sprinkle the chopped hazelnuts over the filling.
Fold one-third of the dough over the filling, then fold the exposed third on top of that.
Using a rolling pin, roll the dough into one long rectangle.
Using a pizza cutter or bench scraper, cut the dough into 1½-inch strips.
Working one at a time, twist each strip, then roll it up into a knot.
Place on a parchment-lined baking sheet. Cover and allow to rise for about 30 minutes or until puffy. Glaze with egg, and then bake at 350°F for 12-15 minutes.
Allow the twists to cool slightly before sprinkling with confectioners’ sugar.