8 ounces bittersweet chocolate, melted
3 tablespoons orange liqueur
2 tablespoons light corn syrup
¼ cup powdered egg whites
¾ cup warm water
½ cup sugar
In a large bowl, mix the chocolate liqueur and corn syrup. In another large bowl, combine the powdered egg whites and warm water, stirring until the powder dissolves completely, about two minutes. With an electric mixer on low speed, beat until foamy, increase the speed to medium, and beat until soft peaks form. While mixing, slowly add the sugar. Increase the speed to medium-high, and continue beating until stiff glossy peaks form.
With a rubber spatula, stir about one third of the meringue into the chocolate mixture. Stir well, then fold in another third of the meringue. Gently fold in the remaining meringue until completely blended. Refrigerate the mousse covered until firm, at least three hours.