Directions
Preheat the over to 375ºF [190ºC]. Butter the insides of 6 ½ cup [120 ml] ramekins. Dust with sugar to coat. Shake out any excess sugar. Divide one third of the chocolate pieces among the ramekins.
Melt the remaining chocolate and milk together using a hot water bath or the microwave oven. Stir until completely melted and smooth. Remove the bowl from the water if you used a hot water bath and set aside to cool for 5 minutes. Whisk in the eggs yolks. Set aside.
In the clean, dry bowl of a stand mixer fitted with the whisk attachment (or in a large bowl using a hand mixer fitted with whisk beaters), beat the egg whites and cream of tartar on medium high speed until foamy. Gradually add the sugar and continue beating until soft peaks form. Gently whisk one third of the egg white mixture to lighten it, then gently whisk the chocolate mixture into the remaining egg white mixture until just combined, being careful not to overmix so the egg white mixture won't deflate. Divide the soufflé batter evenly among the prepare ramekins, filling to cover the chocolate pieces.
Bake for 12 to 15 minutes, or until the tops are puffed and crusty. Serve immediately.
This recipe is courtesy of Amy Guittard from her Guittard Chocolate Cookbook.