Preheat your oven to 350°F (175°C) and line two baking sheets with parchment paper.

Separate the eggs, whipping the yolks with half the sugar until pale and fluffy. Add vanilla extract and lemon zest.

Whip the egg whites until soft peaks form, then gradually add the remaining sugar until stiff peaks form.

Gently fold the egg whites into the yolk mixture.

Whisk together flour, cornstarch, and salt, then fold into the egg batter.

Pipe the batter into 3-inch long 'fingers' on the baking sheets.

Dust the piped cookies lightly with powdered sugar, then bake for 12-15 minutes until golden.

Cool on the tray for a few minutes before transferring to a wire rack.