01 - Preheat oven to 325°F. Arrange four 6 oz ramekins in a deep baking dish.
02 - Combine heavy cream and whole milk in a saucepan over medium heat. Bring to just simmering, then remove from heat. Add chopped chocolate and whisk until completely melted and smooth.
03 - Whisk together egg yolks, 1/4 cup sugar, vanilla extract, and salt in a bowl until well combined.
04 - Slowly pour warm chocolate cream into egg mixture while whisking continuously to prevent curdling.
05 - Pour mixture through a fine-mesh sieve into a measuring jug for smooth texture. Divide evenly among prepared ramekins.
06 - Pour hot water into baking dish until it reaches halfway up sides of ramekins.
07 - Bake for 30-35 minutes until custards are just set but still slightly wobbly in center.
08 - Remove ramekins from water bath and cool to room temperature. Refrigerate for at least 2 hours until completely chilled.
09 - Sprinkle 1 teaspoon sugar evenly over each chilled custard. Use kitchen torch to caramelize until golden and crisp, or broil under preheated broiler. Let stand 2 minutes to harden before serving.