Microwave chocolate morsels and whipping cream in a 3-qt. microwave-safe glass bowl at HIGH 2 1/2 minutes or until melted and smooth, stirring at 30-second intervals. Whisk in liqueur until smooth. Cover and chill 2 hours or until mixture is thickened.
Beat ganache at medium speed with an electric mixer 20 to 30 seconds or until soft peaks form and ganache lightens in color. (Do not overmix.) Use immediately.