Bittersweet Chocolate and Cointreau Mousse

I got this recipe from my Le Cordon Bleu book. I used bitter sweet chocolate instead of semi sweet; I prefer the bitter sweet chocolate but any chocolate can be used.

Ingredients:

4 oz Bitter sweet chocolate (I used the E.Guittard 72% cacao)
3 Tb unsaulted butter
1/4 cup orange juice
3 tb cocoa butter
3 eggs, separated
2 tb Cointreau
1/3 cup whipping cream
1 egg white
2 tb sugar

Directions:
1. Place chocolate butter and oj in a double boiler to melt, in a simmering water
2. When melted, stir in cocoa powder. Remove from water and whisk in egg yolk and cointreau. Let cool.
3. Beat the cream until soft peaks.
4. Beat all the egg whites until soft peaks. Add sugar until smooth.
5. Using a large spoon, gently fold egg whites into the cooled chocolate mixture. Before they are completely incorporated, fold in the whipped cream.
6. Spoon into individual serving dishes.