Preheat oven to 160 conventional
Separate eggs, beat yolks with 1/2 cup sugar until light and creamy
Beat in milk, sifted flour, lemon rind and juice, and salt
Beat egg whites until soft peaks form.
Add extra sugar, beat until sugar is dissolved and fold into lemon mixture
Pour into greased deep 1L oven proof dish, stand in shallow pan of cold water
Bake for 50-60 minutes