1. 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. Stir in chocolate chips. Refrigerate 15 minutes.
2. Line 8-inch square pan with parchment paper, with ends of paper extending over sides of pan. Press 1/2 of the dough into pan until smooth and even. Place a second layer parchment paper on top on the dough and repeat with remaining dough. Freeze for 30 minutes up to 1 hour.
3. Remove from freezer. Carefully remove the top layer of cookie dough by lifting the top layer of parchment paper. Gently spread the softened ice cream over the bottom layer of cookie dough still in the pan.
4. Peel the parchment paper from the second layer of cookie dough and place it smooth side up on top of the ice cream. Cover with foil or plastic wrap. Freeze 2 hours or until firm. Cut into 16 bars. Wrap each in plastic wrap. Store in freezer.
If you make these, I would LOVE to hear about how they turned out.