Melt Dark Chocolate and Butter over double boiler.
Sprinkle in sugar. Stir.
Add all the eggs.
Whisk just to mix but don't incorporate any air.
Add any flavorings at this point.
It should look like a cake batter.
Prepare your cake pan by lining it with a layer of parchment paper. If you choose to make the ramekin version and plan on serving it in the Ramekins then go ahead and pour it straight in. (No greasing anything when using this recipe); either parchment paper or nothing.
Place cake pan or ramekins in a deep enough vessel that you can fill with water at least half way up the depth of the cake pan or ramekin.
I recommend putting the whole thing in the oven first, then using a tea pot to fill with water.
Bake in water bath at 300 Degrees F.
Set timer at about 1 hour. Can sometimes take up to an hour and a half. Should be done when the surface starts to split a little and the mixture is set. It will resemble the top of a browny.
Let cool. And chill overnight before serving.
*This recipe is one I learned in Culinary school. I made a few adjustments but I'd like to cite The Arizona Culinary Institute just in case.