Begin by combining 1 cup of heavy cream and 1 cup of whole milk in a medium saucepan. Heat over low flame until the mixture simmers gently, then remove from heat and stir in 2 tablespoons of Thai tea mix. Allow the tea to steep for 15 minutes, then strain the mixture to remove tea leaves.

In a separate bowl, whisk together 6 egg yolks, 3/4 cup of granulated sugar, and 1 teaspoon of vanilla paste until well combined and the mixture turns a light pale color.

Slowly drizzle the warm cream mixture into the egg yolk mixture while continuously whisking to temper the eggs, ensuring a smooth consistency without curdling. Strain the custard again.

Preheat your oven to 300°F (150°C). Carefully pour the custard mixture into 6 individual ramekins and place them in a baking pan filled with boiling water halfway up the sides of the ramekins.

Bake for 35-40 minutes or until the custards are set but still slightly wobbly. Remove from water bath and cool to room temperature, then refrigerate for at least 2 hours.

Just before serving, sprinkle a thin layer of granulated sugar evenly over the tops and use a kitchen torch to melt the sugar until caramelized.