Preheat oven to 425 degrees F (220 degrees C). Lightly grease a baking sheet.

Unfold the puff pastry on a lightly floured surface, and roll out to a rectangle of about 20x9 inches. Spread the chocolate hazelnut spread over the pastry, then scatter hazelnuts over the top.

Roll the long sides of the pastry rectangle toward the center; where they meet in the center, dampen with water to secure. Using a sharp knife, cut into about 1/2-inch slices; place in the baking sheet, and sprinkle with powdered sugar.

Bake in preheated oven until golden brown, about 10 to 15 minutes.