01 - Preheat the oven to 325°F. Place 4 ramekins (6 oz each) in a deep baking dish.
02 - In a saucepan, heat the heavy cream and milk over medium heat until just simmering. Remove from heat, add the chopped chocolate, and whisk until smooth.
03 - In a bowl, whisk the egg yolks, 1/4 cup sugar, vanilla extract, and salt until well combined.
04 - Gradually pour the warm chocolate cream into the egg mixture, whisking constantly to prevent scrambling.
05 - Strain the mixture through a fine-mesh sieve into a jug to ensure a silky texture.
06 - Divide the custard evenly among the ramekins.
07 - Pour hot water into the baking dish to reach halfway up the sides of the ramekins.
08 - Bake for 30–35 minutes, or until the custards are just set but still slightly wobbly in the center.
09 - Remove ramekins from the water bath and let cool to room temperature. Then refrigerate for at least 2 hours, or until thoroughly chilled.
10 - Just before serving, sprinkle 1 teaspoon sugar evenly over each custard. Caramelize the sugar with a kitchen torch (or under a preheated broiler) until golden and crisp. Allow to cool for 2 minutes, forming a crackly top.