Drain the raisins and separate the eggs. Set the egg whites aside.
On medium-high heat, bring the Creme Fraiche to a boiling point.
Meanwhile in a food processor, grind the chocolate until very fine. Pour the hot Creme Fraiche through the feed tube in a steady stream. Process a few seconds until smooth. Add the egg yolks, one at a time, to the hot chocolate mixture and process for a few seconds to incorporate. Transfer to a large bowl, stir in the drained raisins and cool completely.
In a large mixing bowl, beat the egg whites until stiff peaks form. Gently fold in 1/4 of the beaten whites into the cooled chocolate mixture. When incorporated, fold in the remaining egg whites.
Pour the mousse into the serving dishes, cover tightly with plastic wrap. Refrigerate for at least 4 hours and as long as 12 hours.