1 thin-skinned lemon
2 small or 1 large thin-skinned lemons
2 level tsp baking powder
50驳/1戮辞锄 caster sugar
275驳/9戮辞锄 caster sugar
175g/7oz fondant icing sugar
175g/6oz icing sugar
275驳/9戮辞锄 self-raising flour
275驳/9戮辞锄 softened butter
50驳/1戮辞锄 soft butter
4 free-range eggs
250g/9oz full-fat Italian mascarpone