1. Combine chocolate and 2 tablespoons (30 mL) cream in top of double boiler; heat over simmering water, stirring occasionally, until smooth. Stir in liqueur; remove from water. Let stand at room temperature to cool slightly, 10 minutes.
2. Combine remaining cream and the vanilla in chilled small mixer bowl; beat until stiff. Fold in chocolate mixture; refrigerate until ready to use.