Preheat the oven to 400 F. Butter and flour four 4-ounce ramekins.
Combine the chocolate and the butter in a double boiler and melt. Stir the cocoa powder into the chocolate/butter mixture.
In another bowl, beat the egg whites on medium speed until they form soft peaks. Increase the beater speed to high and gradually add the granulated sugar. Continue beating until the whites are stiff and glossy, but not dry.
Whisk about ¼ of the egg mixture into the chocolate. Gently fold in the remaining egg whites.
Fill the ramekins about 2/3 full with the mixture and bake for 6 to 8 minutes. The tops should be slightly firm, but the center should still be soft.
Mixed Berry Coulis
½ pint fresh raspberries
½ pint fresh blueberries
½ pint fresh strawberries
3 tablespoons sugar
1 tablespoon fresh lemon juice
1 tablespoon Grand Marnier
Combine the berries, sugar, and lemon juice in a saucepan. Heat, stirring, until the fruit is softened.
Remove from the heat and puree in a food processor until very smooth.
Strain the mixture through a sieve to remove seeds.
Stir in the Grand Marnier. Chill.
Serve the chilled coulis over warm cakes. Garnish with sprigs of mint.