Delight of Raspberries

Mix the cornflour with a little cold milk. Add the sugar to the rest of the milk and bring to the boil. Pour half the boiling milk on to the cornflour paste, stirring well, then pour it back into the pan with the remaining milk. Boil for 3 minutes, holding the pan above the heat to avoid the mixture sticking. Allow the mixture to cool for 10 minutes and then stir in the double cream, beating well