Source: She's Becoming Doughmesstic
from Dorie Greenspan’s Baking: From My Home to Yours
6 ounces bittersweet Chocolate, finely Chopped
1/2 Cup plus 2 Tbs. Sugar
1/3 Cup Whole Milk, at Room Temperature
4 Large Eggs, Separated and at Room Temperature
2 Large Egg Whites, at Room Temperature
Confectioner’s Sugar, for dusting
Getting Ready: Position a rack in the lower third of the oven and preheat the oven to 400 degrees F. Give the inside of a 6-7 cup soufflé mold a thick coating of butter, sprinkle it with sugar and tap out the excess. Refrigerate until needed. Line a baking sheet with parchment or a silicone mat.
Put the chocolate and 1/2 cup of the sugar in a heatproof bowl over a saucepan of simmering water and heat, stirring often, until the chocolate is melted. Transfer the bowl to the counter and whisk in the milk. let the chocolate cool for about 5 minutes, then, one by one, whisk in the yolks.
Working in the clean, dry bowl of a stand mixer fitted with a whisk attachment or in a large ol with a hand mixer, whip the 6 egg whites until they just turn opaque and start to hold peaks. Still beating, add the reamining 2 tablespoons sugar in a slowish, steady stream and continue to beat until the peaks are glossy and almost firm. Stir one-quarter of the whites into the chocolate to lighten it, then use a rubber spatula to gently fold in the remaining whites.
Delicately turn the batter into the prepared mold and lightly sprinkle the top with confectioners sugar. Put the mold on the baking sheet.
Bake-it’s better not to open the door and peek until you think the soufflé is almost done-for 40 minutes, or until the soufflé is beautifully puffed and a thin knife inserted into the center comes out clean (find a noncrusty part of the soufflé and gently insert the knife at an angle). Remove the soufflé from the oven and serve immediately, dusting the top with more confectioners sugar if you’d like.