This triumphant cake is based on the colourful iced cassata cakes you see all over Sicily, only it is a much lighter version that is not difficult to make. There is an expression in Sicilian dialect, ‘You are as beautiful as a cassata’ – how romantic to be likened to a cake! If you can find potato flour, do use it as it will make the sponge lighter; if not, use cornflour. You can find potato flour in Asian shops or Italian delis. If you can get hold of sheep’s ricotta all the better, for these cakes are traditionally made with ewe’s milk, which has a pleasant, tangy taste.