1. Preheat the oven to 200°C (over and under heat).
2. Unroll the puff pastry sheet on a flat surface. If frozen, allow it to thaw for 10-15 minutes before use.
3. Spread an even layer of hazelnut spread over the entire puff pastry sheet. Be careful not to add too much to avoid it getting messy when folded.
4. Fold the puff pastry in half, covering the filling inside. Press lightly with your hands to ensure an even thickness.
5. Use cookie cutters (e.g., hearts, stars, or other festive shapes) to cut out figures from the folded puff pastry. Place the shapes on a baking tray lined with parchment paper.
6. Beat the egg and brush a thin layer over each shape. This will give them a golden, shiny finish after baking.
7. Bake the shapes in the middle of the oven for 10-12 minutes, or until golden and crispy.
8. Let the shapes cool slightly, then dust with powdered sugar for a festive touch.