Preheat the oven to 150°C/300°F/gas 2 and line a deep roasting tray with greaseproof paper, then place 6 ramekins or ovenproof moulds inside. Sprinkle 100g of the sugar into a non-stick frying pan, add 3 tablespoons of water and place on a medium heat for about 8 minutes, or until you’ve got a chestnut brown caramel – don’t be tempted to stir or taste it, just gently swirl the pan occasionally. Quickly and carefully divide the caramel between the ramekins. Halve the vanilla pod lengthways and scrape out the seeds, then put both the pod and seeds into a saucepan, along with the milk. Bring almost to the boil, then switch off the heat. Meanwhile, place 2 whole eggs and 4 egg yolks in a bowl (save the whites for making meringues another day) and whisk with the remaining sugar for 1 minute. Slowly pour in the hot milk, whisking continuously. Discard the vanilla pod, and skim away any foam from the top.
Divide the custard between the ramekins, then carefully half-fill the tray with boiling kettle water and bake for 30 minutes, or until just set and a sharp knife comes out clean. Leave to cool completely in the water, then remove, cover and transfer the crème caramels to the fridge for at least 4 hours, or overnight. To serve, dip the base of each ramekin into a bowl of boiling water for 1 minute to loosen, then run a knife around the edge and confidently turn out on to a plate, shaking slightly to loosen, if needed. Squeeze half a passion fruit over each, to serve.
