1Heat oven to 350° F (325° F for dark or nonstick pans). Grease or spray 8-inch square pan.
2Make brownies as directed on box, using water, oil, and eggs. Spread into pan. Bake 39 to 42 minutes or until toothpick inserted 2 inches from edge of pan comes out clean. Cool completely.
3In medium bowl, beat cream cheese, powdered sugar, 2 tablespoons butter and liqueur with electric mixer on high speed until smooth and creamy. Spread over cooled brownies.
4In small microwaveable bowl, microwave chocolate chips and butter uncovered on High 1 to 2 minutes, stirring once, until melted. Carefully spread over filling. Refrigerate 30 minutes or until set. Store in refrigerator.