PREPARATION:

1. Line 8- or 9-inch square pan with foil, leaving 1-inch overhang on sides. Lightly butter foil.
2. Combine butter and brown sugar in small bowl. Stir in flour and 1/4 teaspoon salt. Stir in 1/3 cup chips.
3. Form dough into ball. Place on plastic wrap; flatten into disc. Wrap in plastic wrap and freeze 10 minutes or until firm.
4. Unwrap dough and cut into 1/2-inch pieces; refrigerate.
5. Place powdered sugar, cream cheese, vanilla and remaining 1/4 teaspoon salt in large bowl. Beat with electric mixer at low speed until combined. Scrape down side of bowl; beat at medium speed until smooth.
6. Melt remaining 1 cup chips in heavy small saucepan over very low heat, stirring constantly. Remove from heat as soon as chocolate is melted.
7. Add melted chocolate to cream cheese mixture; beat just until blended. Stir in chilled cookie dough pieces.
8. Spread evenly in prepared pan. Score into squares, about 1-1/4X1-1/4 inches, while fudge is still warm.
9. Refrigerate until firm. Remove from pan by lifting fudge and foil using foil handles. Place on cutting board; cut along score lines into squares. Remove foil. Store in airtight container in refrigerator.