Prepare the Cream: Preheat the oven to 300˚F. Heat heavy cream in a medium saucepan over medium heat until steaming, then add vanilla extract and remove from heat.
Mix Egg Yolks and Sugar: In a bowl, whisk together the egg yolks, sugar, and salt until blended.
Combine Cream and Eggs: Slowly drizzle the hot cream into the egg mixture while whisking constantly. Strain the mixture through a fine-mesh sieve into a measuring cup.
Prepare the Ramekins: Divide the custard mixture evenly into 6 ramekins and place them in a 9×13 baking dish. Add boiling water to the dish, filling it halfway up the sides of the ramekins.
Bake the Custard: Bake at 300˚F for 30-35 minutes, or until the custard is nearly set with a slight wiggle in the center. Remove from water and let cool to room temperature, then refrigerate for 2 hours or up to 3 days.
Caramelize the Top: Just before serving, sprinkle 1 1/2 to 2 teaspoons of sugar on each custard and torch the top until deeply caramelized. Serve immediately.