First, separate the egg whites from the yolks. Set aside.
Melted the chocolate and the butter in a double boiler. Turn off the heat and add the egg yolks stirring vigorously. Set aside.
Beat the cream until firm and place it in the fridge to keep it cold.
Beat the egg whites, first at a low speed and then faster. When they are almost firm, add the sugar, little by little, and continue beating until they are firm enough to make a meringue. It's ready when the egg white mixture is firm and peaks form on the rods, which do not come off and remain rigid. The stiff egg whites are so cohesive that you can tip the bowl over and the whites won´t fall out of it.
Add the meringue to the chocolate, little by little, with a rubber spatula and involving movements. Once we fully incorporate the meringue, we do the same with the cream, incorporating it little by little with involving movements.
Let's chill in the fridge for at least 3 hours. Serve with fresh fruits or whipped cream.