Preheat oven at 375°F.
Grease insides of ramekins and sprinkle with sugar to coat. Stack two single broken pieces of chocolate in each ramekin. Place on baking sheet for easy handling.
Melt remaining four oz (2 bars) chocolate with the milk or water.
Whisk in egg yolks until smooth and glossy.
Put egg whites and cream of tartar in mixer bowl with whisk attachment. Whip at medium-high speed until foamy.
Gradually add sugar and continue whipping to form soft peaks.
Whisk 1/3 of the whites into chocolate mixture to lighten and then gently fold into the remaining whites until almost uniform.
Divide evenly among ramekins, filling to cover chocolate pieces.
Bake about 12-15 minutes or until tops are puffed and crusty.