Preheat oven to 150C/130C fan forced. Bring cream, milk and vanilla bean almost to the boil in a saucepan over medium heat.
Remove the vanilla bean. Scrape the seeds from the bean into the cream mixture. Discard the bean.
Meanwhile, whisk the egg yolks and caster sugar in a heatproof bowl until well combined.
Whisk the cream mixture into the egg mixture. Strain into a jug. Divide among four 185ml ovenproof ramekins.
Place ramekins in a roasting pan. Add boiling water to reach halfway up the sides. Bake for 35 minutes or until just set
Cool slightly. Cover. Place in fridge for 4 hours, until set. Sprinkle raw sugar over custards. Caramelise with a kitchen blowtorch.
