- With the rack in the middle position, preheat the oven to 150 °C (300 °F).
- In a saucepan, bring cream, milk, rum and vanilla to a boil. Remove from heat, cover and let steep for 10 minutes. Remove vanilla bean half.
- In a bowl, combine egg yolks and sugar with a whisk. Gradually add hot cream mixture, whisking constantly. Pour into six 125 ml (½ cup) ramekins.
- Prepare a water bath: place a dishcloth or silicone baking mat at the bottom of a large baking dish. Top with ramekins and pour hot water halfway up ramekins. Bake for about 40 minutes or until custard is slightly firm. The water should not boil, it should barely simmer.
- Remove from water bath. Let cool. Cover with plastic wrap and refrigerate until completely chilled, about 6 hours.
- To serve, sprinkle with sugar and quickly caramelize using a small culinary torch or crème brulée iron. Serve immediately.