1. Heat the oven to 190°C/375°F/gas 5 and line a muffin tin with paper muffin cases.
2. Sift the flour, bicarbonate of soda and salt together.
3. In a large bowl, mix the butter, sugar, eggs, milk, lemon juice and zest, desiccated coconut and raisins (if using) together.
4. Gently fold the flour mixture into the wet mixture, trying not to fold more than 20 times. It's ok if there are lumps of flour as this will make a lighter muffin.
5. Quickly fill the muffin cases. The batter will have started to rise so be as quick as you can.
6. Sprinkle with some coconut flakes (if using).
7. Bake in the centre of the preheated oven for 20-25 minutes, or until the muffins are golden brown and well risen.
8. Leave to cool in the tin for a few minutes before transferring them to a wire rack. Eat warm.