Preheat your oven to 325 °F (160 °C) and prepare a pot of water for the water bath.

In a large bowl, whisk together the egg yolks, white sugar, vanilla extract, and salt until thickened and pale.

Heat the heavy cream in a medium saucepan over medium heat until just about to boil.

Slowly pour the hot cream into the egg mixture while whisking continuously to combine.

Pour the custard mixture into ramekins and place them in a roasting pan. Fill the pan with hot water halfway up the sides of the ramekins.

Bake for about 35 minutes until the edges are set and the centers are slightly jiggly.

Cool the ramekins at room temperature for about 30 minutes, then refrigerate for at least 2 hours.

Before serving, sprinkle sugar on top of each custard and caramelize it using a kitchen torch or under the broiler.