Preheat the oven to 325°F (162°C).
In a saucepan, heat heavy cream and salt over low heat until hot. Remove from heat and let sit for a few minutes, then stir in vanilla extract.
In a separate bowl, whisk together egg yolks and sugar until light and smooth.
Slowly whisk in about ¼ of the warm cream mixture to temper the eggs, then pour the egg mixture into the rest of the cream and stir until fully combined.
Pour the mixture into 6-oz ramekins.
Fill a baking dish ⅓ of the way with hot water, then gently place the ramekins inside (ensuring no water gets in).
Bake for 30-40 minutes, or until the centers are barely set.
Cool completely and refrigerate for several hours or overnight.