In a medium sized saucepan over medium-high heat, add the heavy cream, sugar, liqueur, and vanilla. When the mixture is warm add the cocoa powder and chocolate and whisk until blended.
Place the egg yolks in a large stainless steel bowl. Slowly add the warm chocolate mixture to the eggs a little at a time while whisking. Strain and pour into individual porcelain ramekins. Place the ramekins in a large baking pan. Pour enough hot water into the pan to come half way up the sides of the ramekins. Bake until firm in the center, about 30 minutes. Remove the ramekins from the water bath and let cool completely. Place in the refrigerator for 2 hours. Dust with sugar and caramelize with a propane torch. Serve immediately.