The night before you’d like to drink your milk tea, make the crème brûlée, then chill overnight. Preheat your oven to 250F. In a medium bowl, whisk together the sugar and egg yolks until combined. Add the heavy cream and vanilla extract, and stir to combine.
Place a 1 ½ cup capacity ovenproof container in a baking pan with high enough sides so that water can be poured into reach about halfway up the container. Boil a medium pot’s worth of water. Pour the custard mixture into the ovenproof container. Open your oven, and pull out the oven rack slightly, then place the baking pan (with the container filled with custard) on the rack. Gently pour the boiling water into the baking pan, making sure not to splash the water into the custard. Keep pouring the boiling water until it reaches or slightly is above the level that the custard is at. Gently push the oven rack back in and close the oven.
Bake for 35-40 minutes, or until the custard is set. If it looks liquidy, bake for 5 more minutes, then check again. It should be wobbly in the center, but not liquidy. Remove the custard from the water bath, then let cool at room temperature. Refrigerate until cold