Steps
1. Preheat your oven to 150°C (300°F).
2. In a small saucepan, heat the heavy cream until it just begins to simmer. Remove from heat.
3. Whisk together the egg yolk and granulated sugar in a bowl until pale.
4. Slowly pour the hot cream into the egg mixture while whisking continuously.
5. Stir in the vanilla extract.
6. Pour the mixture into a small ramekin.
7. Place the ramekin in a baking dish and add hot water to the dish, reaching halfway up the sides of the ramekin.
8. Bake for 35-40 minutes, until the custard is set but still slightly jiggly in the center.
9. Remove from the oven, cool to room temperature, then refrigerate for at least 2 hours.
10. Just before serving, sprinkle the brown sugar evenly on top and use a kitchen torch to caramelize it until golden and crispy.
11. Allow the sugar to harden for a minute before serving.