Pre-heat the oven to gas mark 2, 150°C. First, pour the caramel sauce into an 850ml ovenproof dish to cover the base.
Then, combine the milk and cream in a saucepan and heat them gently.
Meanwhile, in a bowl, whisk together the eggs, sugar and vanilla extract, then pour the hot milk and cream in to join them and give another good whisk.
Pour all of this into the dish, place it in a small roasting tin, then pour enough boiling water into the tin to come about two-thirds of the way up.
Transfer it to the oven and cook on the centre shelf for 1 hour.
When the crème caramel has cooled, chill it well in the fridge.
To serve, you will need a serving dish deep enough to cope with the caramel sauce. Slide a palette knife all round the edge before inverting it on to the serving dish.
Serve, cut into wedges with lots of sauce poured over – some chilled pouring cream would make it even more special.