Dream come true Chocolate Cake

I might be slightly biased but I sincerely believe that this chocolate cake is the most delicious one in the world. It's nice and crunchy on top but it's so soft and creamy in the center that it will melt in your mouth. My dad (who's a teacher) got the recipe from one of his students' mom who brought this cake to class one day (perhaps 10 years ago...) for her son's birthday party. Since then no one in my family would even consider trying another chocolate cake recipe :-)

• 4 eggs
• 3/4 cup (170 grams) sugar
• 6 ounces (170 grams) butter
• 6 ounces (170 grams) semi-sweet (dark) chocolate
  
• 1/2 cup (50 grams) all-purpose unbleached flour

1. Break the chocolate in small pieces and cut the butter in small slivers. Slowly melt them in a double boiler. You could also use a small sauce pan placed in a larger pot in which you pour water. The water should be almost boiling but not quite. Stir gently. The mixture will become shiny and smooth. This technique has the cute name of "Bain Marie".
   
2. Break the eggs and separate the whites from the yolks.
   
3. Mix together the egg yolks and the sugar in a large bowl. Stir well (with a wooden spoon) until the mixture becomes foamy and almost white. If you lift the mix with the spoon it should run down like a ribbon ("au ruban". French cuisine is always so poetic!).
4. Add the melted butter and chocolate and stir well.
5. Then incorporate the flour (sift it to avoid lumps).
6. Beat the egg whites until you obtain a thick and firm white foam (called "snow" in French...).
7. Incorporate them delicately to the dough, 1 tablespoon at a time, with an "under-and-over" motion.
8. Pour the dough in a round cake pan (about 9" in diameter) lined with buttered aluminum foil or baking paper. The difficult part in this recipe is to unmold the cake...
9. Bake at 350F until a crust forms on top, about 15-20 minutes. Turn off the oven as soon as the curst is formed but let the cake cool down in the oven without opening.

The crust might break into pieces when you unmold the cake... I haven't found a way yet to prevent this from happening. But never mind: the cake is divine!

Pictures added on April 22, 2006