Batter may be made 12 hours before baking.
1 tablespoon butter or margarine for greasing
1/2 cup plus 1 tablespoon sugar
5 large eggs, separated, whites at room temperature for at least 2 hours
8 ounces bittersweet chocolate, broken into small pieces
If baking immediately, preheat oven to 350 degrees. Rub the butter or margarine around the sides and bottoms of 6 small ramekins. Add the tablespoon sugar to one, turn to coat and then tap out excess into the next ramekin. Repeat until all coated, using more sugar if needed. Place on a cookie sheet and refrigerate.
In a medium bowl, place the egg yolks and 2 tablespoons of the 1/2 cup of sugar. Mix vigorously with a hand whisk. Melt the chocolate either in a double boiler or in a microwave-safe bowl in the microwave: heat for one minute and mix well, another 45 seconds and mix well and then 30 seconds and mix well, each time stirring the unmelted pieces into the melted parts. Add the chocolate to the egg yolk mixture and whisk.
Beat the egg whites on high speed until thick. Turn the mixer speed to low, add the remaining sugar, about a tablespoon at a time, and when all added, turn the speed up to high for 30 seconds or until whites are shiny and stiff.
Mix whites into the chocolate mixture in four parts, mixing a little slower each time until all the whites are mixed in. Divide among the ramekins. If baking later, cover with plastic and refrigerate until baking. Bake for 18 minutes. Dust with confectioner’s sugar and serve.