1. Arrange eight 4-ounce ramekins or small coffee cups on a baking sheet. Heat the half-and-half, sugar and salt in a pot over medium heat until it just comes to a boil. Whisk the egg yolks with the cognac and vanilla in a medium bowl. Whisk about 1/2 cup of the hot half-and-half into the yolks until smooth and then whisk the egg mixture back into the pot. Continue to cook until the mixture thickens slightly, stirring constantly, 2 to 3 minutes. Place the chocolate in a large bowl and pour the hot cream mixture over the chocolate. Whisk until smooth and then lightly stir to remove any air bubbles.
2. If the mixture is not completely smooth, pour through a strainer and then divide evenly between the ramekins. Chill until cold and set, at least 2 hours or overnight. Serve with a dusting of cocoa powder, whipped cream and/or a sprinkle of nuts, coconut or chocolate curls.