HEAT broiler.
ARRANGE crackers in center of 12-inch pizza pan, with crackers slightly overlapping and leaving a 3-inch border around edge of pan.
TOP with 1/3 cup mozzarella, zucchini and peppers; cover with sauce, remaining mozzarella, Parmesan and oregano.
BROIL 2 to 3 min. or until mozzarella is melted.