Pan di Spagna, Pasta Margherita, Pasta Maddalena

Pan di spagna is a basic soft, sweet sponge cake, made by beating together 6 egg yolks with 250 g (9 oz) caster sugar until you have a foamy mixture. Add to this the beaten whites of the six eggs and a pinch of salt. Slowly add 150 g (5 oz) fine 00 (doppio zero) flour and 150 g (5 oz) potato flour, stirring carefully with a wooden spoon. Add a few drops of vanilla essence or the seeds of one vanilla pod, and the finely grated zest of ½ lemon. Pour the mixture into a high-sided baking tray that has been buttered and dusted with flour. Bake for 30 minutes at 180°C/350°F/gas 4, then remove and allow to cool. Cut in half and fill with cream, jam, custard or chocolate.