Pre-heat oven to 350 ° F.
Lightly butter ramekins and dust lightly with sugar. Place on a cookie sheet and set aside.

In a double boiler, over simmering hot water, met the chocolate, stirring occasionally until smooth. Remove from heat.
In a small saucepan melt the butter over medium heat. Stir in the flour and cook until thickened, but not brown, 1 - 2 minutes.
Add the milk and whisk briskly until smooth and thick, about 3 minutes. Remove from heat and add in the melted chocolate and whisk until smooth.
Whisk in the egg yolks and vanilla, set aside.

In a medium bowl, using an electric mixer if you have one, beat the egg whites and cream of tartar at medium speed until soft peaks form, about 1 minute.
Gradually sprinkle the fine white sugar on top and beat at high speed until the whites are stiff., but not dry. Using a rubber spatula, fold ¼ of the whites into the chocolate mix to lighten it, then fold in the remaining whites.

Spoon the mixture into ramekins (¾ full) (can be prepared up to one day in advance to this stage, cover with plastic wrap and refrigerate).

Bake 15-17 minutes, until puffed and slightly cracked.
Dust the souffles with confectioners sugar and serve with whipped cream and berries, if your using them. Serve immediately.