Pre-heat oven 150C/300F/Gas 2. Warm the ramekins in the oven, so they are warm when the caramel is poured in.
First make the caramel. Pour the sugar and six tablespoons of water into a clean stainless steel pan.
Dissolve the sugar slowly, stirring with a wooden spoon over a low heat.
When there are no sugar granules left, stop stirring and boil until the sugar turns a dark copper colour.
Remove immediately from the heat to ensure the caramel does not burn. Quickly pour the caramel into the warmed ramekins.
Set aside to cool and become hard. (Do not put in the fridge because the sugar will absorb moisture and go soft and tacky).
Once hard, butter the sides of the ramekins above the level of the caramel.
For the custard, whisk the eggs, vanilla extract and caster sugar together in a bowl until well mixed.
Pour the milk into a saucepan, gently heat over a low heat until you can still just dip your finger in for a moment, then strain the milk through a fine sieve onto the egg mixture in the bowl.
Whisk together until smooth, then pour the mixture into the prepared ramekins.
Stand the ramekins in a roasting tin and fill the tin half-way with boiling water from a kettle.
Cook in the oven for about 20-30 minutes or until the custard has set. Do not overcook the custard – check around the edges of the dishes, to make sure no bubbles are appearing.
Take the crème caramels out of the oven, remove the ramekins from the tray and set on a cooling rack. When cool, transfer to the fridge overnight so that the caramel is absorbed into the custard.
To serve, loosen the sides of the custard by tipping the ramekin and loosen with a small palette knife round the edges. Place a serving dish on top of the ramekin and turn upside down. Serve with pouring cream.
Make these the day before - if you turn the caramel custard out too soon, the caramel stays in the bottom of the ramekins. But do turn them out just before serving or the caramel will lose its colour.
If you prefer, the recipe can be made in a 1.2 litre (2 pint) dish and cooked for 40-50 minutes.
Do not use a non-stick pan to make the caramel, it will not work, it will crystallize. For a richer crème caramel add an extra two yolks to the eggs.