1 lemon, lime, grapefruit or orange, zest only (optional)
340²µâ€“450²µ/12´Ç³ú–1±ô²ú raspberries, fresh or frozen
220g/8oz plain flour
1 tbsp baking powder
275g/9¾oz caster sugar
½ tsp vanilla extract
115g/4oz unsalted butter, melted
3 large free-range eggs
365²µ/12½´Ç³ú ricotta, plus 400g/14oz to serve