Preheat oven to 325°F. In a saucepan, combine heavy cream and vanilla bean (scrape seeds into cream and add pod). Heat over medium until cream just begins to simmer. Remove from heat, cover, and let steep for 15 minutes to infuse vanilla flavor.

In a bowl, whisk together egg yolks, 1/2 cup sugar, and salt until smooth and pale yellow. Remove vanilla pod from cream. Slowly whisk hot cream into egg mixture, adding about 1/4 cup at a time to temper eggs and prevent curdling. Strain through fine-mesh sieve into a large measuring cup with spout.

Divide custard evenly among six 6-ounce ramekins or shallow brûlée dishes. Place ramekins in a large roasting pan. Pour hot water into roasting pan to come halfway up sides of ramekins for even, gentle cooking.

Carefully transfer pan to oven. Bake for 40-45 minutes until custards are set around edges but centers still jiggle slightly when gently shaken, like soft gelatin. Centers will continue to set as they cool.

Remove ramekins from water bath and let cool to room temperature on a wire rack. Cover each with plastic wrap and refrigerate until thoroughly chilled and set, at least 4 hours or overnight.

Just before serving, blot any moisture from custard surfaces with paper towel. Sprinkle 1 teaspoon of sugar evenly over each custard. Use a kitchen torch to caramelize sugar, moving torch constantly until sugar melts and turns deep amber. Let harden for 1 minute before serving.