1. Lightly grease two 3/4-cup capacity ramekins or molds. Line base and sides with a piece of plastic wrap. Allow plenty of overhang.
2. Place chocolate and butter in a heatproof, microwave-safe bowl. Microwave, uncovered, on MEDIUM (50%) for 2 to 3 minutes, stirring every minute with a metal spoon, or until melted and smooth. Allow to cool for 5 minutes.
3. Add liqueur and egg yolks to chocolate mixture. Stir until well combined.
4. Using an electric mixer, beat egg whites and salt in a small bowl until soft peaks form. Add sugar and beat well. Stir a third of egg whites into chocolate mixture. Gently fold remaining egg whites into chocolate mixture. Spoon into prepared ramekins. Fold over excess plastic wrap to cover. Freeze for at least 3 hours or overnight, if time permits, until firm.
5. Using the plastic wrap, gently ease mousse from ramekins. Turn out onto chilled serving plates. Dust with cocoa and serve.
For best results, use 70%-cocoa chocolate.
Makes 2 servings.
Date: June 13, 2007