Place the sugar and water in a heavy based pan, heat gently and stir to dissolve then bring to the boil. Bubble to a golden caramel, remove from the heat and dip the base of the pan into cold water for a moment to stop the cooking. Pour into the moulds and leave to cool and set.
Slowly bring the milk and vanilla pod to the boil.Whisk the eggs, yolks and sugar until pale and thick, pour on the milk and vanilla pod, stir to blend and strain into a jug.
Preheat the oven to 150C/300F/gas2. Pour the egg mixture into the moulds and place them in a deep dish or roasting tin. Pour warm water around to come 2/3 up the moulds.
Bake in the oven for 35-40 minutes or until just set. Remove and leave to cool. Loosen and turn out on to individual plates.