You will need to start the recipe at least one day before so the custards have time to chill.
First place the cream in a pan over a gentle heat and heat it to just below simmering point, stirring occasionally with a wooden spoon.
While the cream is heating, use a balloon whisk to whisk together the egg yolks, sugar and cornflour mixture and the vanilla in a medium bowl with a cloth underneath to steady it.
Then, whisking the egg mixture all the time with one hand, gradually pour the hot cream into the bowl.
When it's all in, immediately return the whole lot back to the saucepan using a rubber spatula.
Now back it goes on to the same gentle heat as you continue whisking until the custard is thick and smooth, which will happen as soon as it reaches simmering point. If you do overheat it and it looks grainy, don't worry, just transfer it to a jug or bowl and continue to whisk until it becomes smooth again.
Now divide the custard among the ramekins and leave to cool. Then cover each dish with clingfilm and refrigerate overnight.
To caramelize the tops, first pre-heat the grill to its highest setting then uncover the ramekins and sprinkle each of the tops evenly with one tablespoon of granulated sugar. Place them on a baking tray and put them under the hot grill for 4-5 minutes until the sugar has melted and started to go very dark brown in some places.
Leave the caramel to harden before serving or you can freeze them as they are in the Iced Chocolate and Vanilla Crème Brûlée recipe below