HEAT oven to 375°F.
HEAT large skillet sprayed with cooking spray on medium heat. Add zucchini and yellow squash; cook and stir 5 min. or until crisp-tender.
BEAT eggs and dressing in large bowl with whisk until well blended. Stir in Parmesan. Add zucchini mixture and all remaining ingredients; mix lightly. Spoon into 8-inch square baking dish.
BAKE 35 to 40 min. or until center is set and edges are lightly browned.