Preheat the oven to 180°C.
Remove the butter from the fridge and allow to soften to room temperature.
Split the vanilla pod in half and scrape out the seeds. Zest the orange.
Mix together the softened butter, sugar and a pinch of salt. Add the egg and mix until smooth. Sift in the flour, add the orange zest and the vanilla seeds and combine before transferring the mixture to a piping bag.
Line a baking tray with baking parchment and then pipe the langues de chat on to the tray. Use a palette knife to gently flatten each langue de chat.
Transfer to the oven and bake for 5 minutes. The biscuits should be golden brown at the edges.
Remove from the baking tray and allow to cool before serving.
«Vary this recipe by dipping the biscuits in melted dark chocolate or sprinkling with poppy seeds or lemon zest.»