Marbled-Chocolate Graham Crackers

Marbled-Chocolate Graham Crackers 8-1/2 graham crackers, broken in half (17 squares) 1-1/2 pkg. (4 oz. each) Semi-Sweet Chocolate (6 oz.) 1/2 cup creamy peanut butter 3 oz. White Chocolate Line 13x9-inch pan with foil, with ends of foil extending over sides. Place grahams on bottom of pan, cutting as needed to completely cover bottom. Microwave semi-sweet chocolate and peanut butter in medium microwaveable bowl on HIGH 1-1/2 to 2 min. or until chocolate is completely melted and mixture is well blended, stirring every 30 sec. Pour over grahams; spread to completely cover grahams. Melt white chocolate as directed on package. Drop spoonfuls over semi-sweet chocolate; swirl gently with knife. Refrigerate 1 hour or until firm. Use foil handles to lift dessert from pan; peel off foil. Cut dessert into bars.