Adapted from Cook's Illustrated
4 tablespoons butter, cut into pieces, plus more for coating ramekins
8 ounces semi-sweet chocolate, chopped
1/2 teaspoon vanilla
1 tablespoon liqueur of choice, I used Frangelico...Grand Marnier was recommended
6 egg yolks
8 egg whites, at room temperature
1/3 cup sugar plus more for coating ramekins
1/4 teaspoon cream of tartar
2 tablespoons powdered sugar, plus more for garnish
Coat 6-8 one cup ramekins with butter, then dust with sugar. Refrigerate till batter made.
Melt butter and chocolate gently in microwave, till melted (I zap for 30 seconds, stir, then repeat till melted). Stir in vanilla, liqueur and set aside.
Bring the 1/3 cup of sugar plus 2 tablespoons of water to boil in small pan. Simmer till sugar is dissolved. In mixer with whisk attachment, mix egg yolks, then slowly add sugar syrup. Beat for about 3 minutes, till yolks triple in bulk. Fold into chocolate mixture and set aside. Wash mixer and attachment well...it must be totally free of any oils in order for the whites to whip properly.
Beat egg whites on medium speed till frothy, a minute or so. Add cream of tartar and increase speed to medium high. Beat to soft peaks, then add powdered sugar. Continue beating till stiff peaks form, about 2-4 more minutes. Whites should be firm enough to support a spatula, but not dry.
Beat a quarter of the egg whites into chocolate by hand with a whisk. Then fold this mixture into the egg whites, folding gently with a large spatula, till just incorporated.