Chocolate & Butterscotch Fudge (Borden's recipe)

1 cup butterscotch chips
14 ounces sweetened condensed milk
2 cups semi-sweet chocolate chips
1 tp vanilla extract
1/2 cup chopped walnuts

Line 8-inch square pan with foil. In small microwaveable bowl, place butterscotch chips and 1/3 cup sweetened condensed milk and set aside. In another microwaveable bowl, place chocolate chips, remaining sweetened condensed milk and vanilla. Microwave at HIGH 1 minute, stir until chips are melted. Stir in walnuts. Spread into prepared pan. Microwave butterscotch chips at HIGH for 45 seconds; stir chips until melted. Spread evenly over chocolate layer. Refrigerate until firm. Remove from pan, peel off foil and cut into squares. Store in refrigerator.