With the zing of fresh lemon and a delicate texture somewhere between a biscuit and a cake, these take moments to make. Measure the ingredients carefully and don’t overbake.
Preheat the oven to 200°C/Gas 6. Lightly oil and line one large or two medium baking sheets with baking paper. In a large bowl, whisk the egg with the oil, vanilla and lemon zest. Add the sugar and whisk until thick, then add the flour and salt and mix thoroughly with a wooden spoon.</