MIX cream cheese spread, dressing, sour cream, 1/2 cup mozzarella and 2 Tbsp. Parmesan until blended; spread onto bottom of microwaveable 9-inch pie plate.
COVER with pizza sauce, remaining cheeses, pepperoni and peppers.
MICROWAVE on HIGH 4 to 5 min. or until dip is heated through and mozzarella is melted.