Difficulty:[usr 2]
Break the chocolate into pieces and melt it in a bain-marie with very little water.
Incorporate the butter cut into pieces, then the sugar. Work the mixture for 1/4 hour.
Add the egg yolks, then the beaten whites.
Pour into a buttered cake tin. Chill in the fridge overnight.
Remove the next day after immersing the bottom of the mold in hot water.
Put back in the freezer for a few minutes just before serving.
Decorate with vanilla whipped cream.
Source:Les Bons Desserts. Baudouin.