Heat oven to 350 degrees F. Coat standard bundt cake pan with nonstick cooking spray. Dust with flour; shake out excess.
With an electric mixer, beat cake mix, melted ice cream and eggs in a bowl on low speed for 1 minute. Beat 2 minutes on medium. Scrape into prepared pan.
Bake at 350 degrees F for 35 to 40 minutes or until toothpick inserted in center comes out clean. Cool in pan on wire rack 20 minutes. Invert onto rack to cool completely.
In large bowl, beat cream cheese, sour cream, butter and liqueur on medium speed until light and creamy, about 2 minutes. On low speed, gradually beat in confectioners sugar, about 1 to 2 minutes. Place in refrigerator while cake cools.
Place cake on stand; spread top and sides with frosting. Refrigerate until ready to serve. Dust top with cocoa powder. Makes 16 servings.