Preheat oven to 325°F (160°C) and arrange six ramekins in a baking dish.

In a saucepan over medium heat, combine heavy cream, milk, and chai spices. Heat until warm but not boiling.

In a bowl, whisk together egg yolks and sugar until pale and fluffy.

Gradually pour the warm cream mixture into the egg mixture while whisking continuously. Stir in vanilla extract.

Strain the custard into ramekins and fill the baking dish halfway with hot water.

Bake for 30-35 minutes until edges are set but centers jiggle slightly. Cool, then refrigerate for at least four hours or overnight.

Before serving, sprinkle sugar on top and caramelize using a kitchen torch or broiler until golden brown.