Two-Layer Fudge

1 pkg. (8 squares) BAKER'S Semi-Sweet Chocolate
1 can (14 oz.) sweetened condensed milk, divided
1/2 cup chopped PLANTERS Walnuts
1 tsp. vanilla 1 pkg. (6 squares) BAKER'S White Chocolate

1. MICROWAVE semi-sweet chocolate and 3/4 cup milk in medium microwaveable bowl on HIGH 2 min. or until chocolate is almost melted, stirring after 1 min. Stir until chocolate is completely melted.
2. ADD nuts and vanilla; mix well. Spread onto bottom of foil-lined 8-inch square pan.
3. MICROWAVE white chocolate and remaining milk in medium microwaveable bowl on HIGH 1-1/2 min. or until chocolate is almost melted, stirring after 1 min. Stir until chocolate is completely melted. Spread over semi-sweet chocolate layer. Refrigerate 2 hours.