1Make cookie dough as directed on package. Spread in bottom of ungreased13x9-inch pan. Bake at 350°F 12 to 15 minutes or until light golden brown; cool.
2Microwave 1 cup chocolate chips uncovered on High 1 to 2 minutes or until melted. In medium bowl, beat cream cheese with electric mixer until smooth. Beat melted chocolate into cream cheese. Beat 1 cup whipping cream with electric mixer on high speed until stiff peaks form. Fold whipping cream into chocolate-cream cheese mixture until well blended. Spread over cooled cookie base. Cover; refrigerate 1 hour or until set.
3Microwave 1 cup chocolate chips uncovered on High 1 to 2 minutes sitrring every 20 seconds or until melted. Whisk or stir in 1/2 cup whipping cream until blended. Spoon warm chocolate mixture over mousse; spread evenly. Refrigerate 30 minutes or until set.