Preheat and Prepare Oven: Set your oven to 325°F (163°C) to ensure it reaches the ideal temperature while you prepare the custard.
Infuse Cream with Vanilla: Pour the heavy cream and whole milk into a medium saucepan. Split the vanilla bean lengthwise and scrape out the seeds. Add both the seeds and the pod into the cream mixture. Stir in the ½ cup of sugar to sweeten.
Heat Cream Mixture: Place the saucepan over medium heat and gently warm, whisking occasionally to dissolve the sugar. Once you see the cream steaming and small bubbles forming along the edges (about 5 minutes), remove from heat. Let it cool slightly for 2 minutes to prevent cooking the eggs in the next step.
Whisk Egg Yolks: While the cream cools, vigorously whisk the egg yolks in a large measuring cup or bowl until they become smooth and slightly pale.
Temper Eggs: Slowly pour a small amount of the warm cream mixture into the egg yolks while whisking constantly. This gradual mixing prevents the eggs from scrambling. Then, continue adding the rest of the cream mixture steadily, whisking until fully combined.
Add Salt and Skim Foam: Stir in the kosher salt to enhance flavor. If you notice any foam on the surface, carefully remove it with a spoon to keep the custard silky and free from bubbles.
Arrange Ramekins and Prepare Water Bath: Place six 4-ounce ramekins into a deep baking dish. Pour the custard evenly into each ramekin. Boil water in a kettle and then pour it around the ramekins in the baking dish, filling the water to about three-quarters up the sides of the ramekins. This water bath will gently cook the custard evenly.
Bake Custards: Carefully place the baking dish in the oven. Bake for 30 to 35 minutes, checking for doneness by gently shaking the dish—the custards should be mostly set but still have a slight wobble in the center.
Cool and Chill: Remove the ramekins from the water bath and transfer to a cooling rack. Allow to cool to room temperature before refrigerating them for at least 3 hours or up to 3 days for the flavors to fully develop.
Caramelize Sugar Topping: When ready to serve, sprinkle 2 teaspoons of granulated sugar evenly over the top of each custard. Using a kitchen torch, carefully caramelize the sugar by moving the flame in small circles until the sugar melts and forms a crisp, golden crust.
Serve or Store: Serve immediately for the best texture, or refrigerate for up to 1 hour before serving. Avoid longer refrigeration after torching, as the caramelized sugar can soften.
