Line a muffin tin with large muffin cases. Heat the oven to 180C/160C fan/gas 4. Tip all the ingredients in a large bowl and mix until smooth using a wooden spoon or an electric whisk. Spoon tablespoons of the batter into the muffin cases until they’re three-quarters full (you can make up to six, depending on the case size). Bake for 30 mins or until a skewer comes out clean. Leave on a cooling rack to cool completely.

Meanwhile, make the icing. Sieve the icing sugar into a bowl and gradually add lemon juice until you have a thick but pourable icing – you may not need all of the juice. Drizzle over the cooled muffins and serve.