Strip the corn and remove all the stringy bits. Remove the kernals. Take the corn centres and break into 3-4 pieces .
Put the corn, the core bits, milk and sugar in a medium saucepan over moderate heat and cook, stirring once in a while, until the corn is tender . Cover and steep for 20-30 minutes to get as much flavour as you can.
Strain the corn and throw away the corn centres. Blend about 2/3 of the kernels with the milk. Stir in the cream, salt, and vanilla, and chill completely.
Pour the mixture into moulds, leaving a bit of room at the top as it expands.