Preheat your oven to 300°F. Warm the heavy cream in a medium saucepan over medium heat, stirring often until it steams and approaches a simmer; incorporate the vanilla, then remove from heat. In a separate bowl, whisk the egg yolks, 1/2 cup sugar, and salt together until fully combined. While continuously whisking, slowly drizzle in the heated cream to temper the eggs, starting gradually to prevent curdling. Pass the custard base through a fine-mesh sieve into a large measuring cup with a spout, discarding any solids left behind. Evenly pour the custard into six 4-ounce ramekins and arrange them in a 9×13-inch baking dish. Carefully pour boiling water into the dish until it reaches halfway up the sides of the ramekins. Bake for 30–35 minutes, or until the centers are mostly set with a slight jiggle remaining. Transfer the ramekins to a wire rack to cool to room temperature, then cover and refrigerate for at least 2 hours or up to 3 days until thoroughly chilled. When ready to serve, sprinkle each custard with 1 1/2 to 2 teaspoons of sugar, tilting to coat the surface evenly. Using a kitchen torch, melt the sugar in a circular motion until it forms a deep golden c