18 graham crackers, divided
1 pkg. (8 oz.) PHILADELPHIA Cream Cheese, softened
16 JET-PUFFED Marshmallow s
1-1/2 pkg. (4 oz. each) BAKER'S Semi-Sweet Chocolate (6 oz.), broken into pieces
1-1/2 pkg. (4 oz. each) BAKER'S White Chocolate (6 oz.), broken into pieces