Lightly butter eight
Separate the eggs, leaving the whites in a large bowl and the yolks in a small one. Lightly beat the yolks. Set it all aside.
Melt the chocolate in a double boiler over barely simmering water, stirring occasionally, and set aside. In a saucepan, melt the butter, add the flour, and cook over medium heat for 2 to 3 minutes. Add the milk and whisk until the mixture is smooth, then bring to a boil. Reduce the heat and continue to cook for 3 to 4 minutes or until the sauce base is very thick. Remove from the heat, and whisk
In a separate bowl, beat the egg whites with the cream of tartar until soft peaks form (they should still be drooping over, not standing up stiffly, when you lift up the beaters). Sprinkle in the
Stir a quarter of the whites into the chocolate mixture to lighten it, and then carefully fold in the remaining whites. Pour the mixture into the prepared soufflé dishes and place on a baking sheet. (You don’t need the baking sheet for a single large soufflé dish.)
Remove from the oven, dust with powdered sugar, and garnish each serving with a spoonful or two of fresh raspberry puree, if desired.