Directions

1. 1. Sift the flour and salt into a medium bowl.
2. 2. Beat the butter and granulated sugar in a large bowl with an electric mixer at high speed until creamy.
3. 3. Add the eggs and lemon zest, beating until just blended.
4. 4. Mix in the dry ingredients and hazelnuts to form a smooth, not sticky, dough.
5. 5. Refrigerate for 30 minutes.
6. 6. Set out four cookie sheets.
7. 7. Fit a pastry bag with a 1/2 -inch (1-cm) round or star tip, twist the opening tightly closed, and squeeze out long strips of dough onto a sheet of parchment paper.
8. 8. Cut into 3-inch (8-cm) lengths and press into S-shapes with your fingers. Use a long spatula to transfer to the prepared cookie sheets, spacing 2 inches (5 cm) apart.
9. 9. Refrigerate for 1 hour.
10. 10. Preheat the oven to 375°F/190°C/gas 5.
11. 11. Bake, one sheet at a time, for 7-10 minutes, or until golden and the edges are firm.
12. 12. Cool on the sheets for 2 minutes until slightly firm. Dip in the vanilla sugar while still warm.
13. 13. Transfer to racks and let cool completely.