Method

Pre-heat fan oven to 180C. Grease with extra butter a 18cm/7in round cake tin, line the base with greaseproof paper & grease the paper as well.

Cream the butter & sugar together in a bowl until pale & fluffy, electric hand mixer is best. Beat in the eggs, one at a time, beating the mixture well between each one & adding a tablespoon of the flour with each egg to prevent the mixture splitting.

Fold in the remaining flour & lemon zest using a silicon spatula.

Tip the mixture into the prepared tin & lightly level the top, bake on the middle shelf of the oven for 30-40 minutes, or until golden-brown on top & a skewer inserted into the centre comes out clean.

Remove from the oven and set aside to cool in the tin for 10 minutes, then turn it out on to a wire rack & leave to cool completely, peel off paper.