1Heat oven to 450º. Spray jelly roll pan, 15 1/2x10 1/2x1 inch, with cooking spray. Toss zucchini, bell pepper, mushrooms, onion and oil to coat; spread evenly in pan. Bake 15 to 20 minutes or until vegetables are crisp-tender.
2Spread pizza crust with marinara sauce. Top with vegetables and cheese.
3Bake 8 to 10 minutes or until hot. Cut into squares or wedges to serve.