Chop up the chocolate and place it in a blender. Set aside.
Place the cream, egg yolks, sugar and salt in a medium saucepan over medium heat, whisking to combine the ingredients. Continue to whisk continually until the mixture just starts to bubble and is thick enough to coat the back of a spoon.
Pour the hot mixture into the blender with the chocolate and vanilla and blend until smooth. Pour the mixture into individual ramekins and refrigerate for 6-8 hours or until set (I often chill them overnight).
Let the pots de creme sit at room temperature for about 10 minutes before serving.Serve with a dollop of whipped cream on top with a sprinkle of grated chocolate or chocolate curls.
This recipe makes 6 small servings (a little over 4 ounces) which is pretty standard given the richness of the dessert. That said, I will freely admit that I regularly make this as 4 servings.