You're supposed to serve it with whipped cream, but when we were ready to eat it, I was not ready to make whipped cream. It would have been nice, but I don't think it's absolutely necessary.
I'll hand the verdict over to Julia. While she was retreating to her room with a large slice to accompany her through her many hours of homework, she told me, "This is the best thing to happen to me all day." I guess it wasn't superfluous after all.
Here's the recipe.
East Hampton Chocolate Icebox Cake
6 oz. ladyfingers (about 40)
7 oz. semisweet chocolate, chopped
9 oz. milk chocolate, broken up
1/2 t. plain gelatin
1 t. cold water
6 large eggs, separated
1/2 t. vanilla
1/4 c. Grand Marnier or Cointreau
1/4 c. (1.75 oz.) sugar
Get out a 9-inch springform and line it with ladyfingers. You can do it as I did in the picture above, but I think Maida wants you to line the sides with the ladyfingers lying horizontally. Of course, that would be impossible with the crunchy ladyfingers...
Melt the chocolate: put the semisweet chocolate in a microwave-safe bowl and microwave 30 seconds. Add the milk chocolate and microwave another 30 seconds. Stir and see if it needs a bit more melting: mine needed another 15 seconds, but I have a weak European microwave. When it's all melted, set aside.
In a small bowl or custard cup, sprinkle the gelatin over the water and let sit while you beat the egg yolks.
In a medium bowl, beat the egg yolks at high speed until they are pale and thick. Stir in the vanilla and about one-third of the Grand Marnier; let stand.
Put some hot water in a small saucepan, put the custard cup in the pan, and place over low heat. Stir with a knife until the gelatin has melted. Then add the hot gelatin all at once to the egg yolk mixture, beating at high speed. Now beat in the melted chocolate.
In a large bowl with clean beaters/whisk attachment, whip the egg whites and salt at high speed until they hold a shape. Reduce the speed a bit and gradually beat in the sugar. Increase the speed again and beat until the whites hold a definite shape. Fold about a third of the beaten egg whites into the chocolate mixture, and then fold the lightened chocolate mixture into the egg whites. Pour this mousse into the ladyfinger-lined springform pan. Cover the pan loosely with a paper towel and then tightly with plastic wrap. Let chill at least 6 hours. When cutting into it, have a tall glass of hot water handy to dip the knife in so that the mousse doesn't stick to the knife. Serve with whipped cream if you'd like. This is supposed to serve 8-10, but it's so rich that it would probably serve more.