Microwave butter and sugars in large microwavable bowl on HIGH 1 1/2 to 2 minutes, stirring after 1 minute.
Stir until mixture is melted and smooth. Stir in milk, vanilla and salt. Add flour; stir until well blended. Refrigerate 15 minutes. Stir in chocolate chips.
Line 8-inch square pan with foil, with ends of foil extending over sides of pan. Press 1/2 of the dough into pan. Roll out remaining dough on lightly floured surface to 8-inch square. Gently spread ice cream over layer on pan. Place 8-inch square layer over ice cream. (If dough layer is too warm, freeze for 15 minutes before placing over ice cream.) Cover with foil.
Freeze 2 hours or until firm. Cut into 16 bars. Wrap each in plastic wrap. Store in freeze