Unroll pizza crust into a 15-in. x 10-in. x 1-in. baking pan coated with cooking spray; flatten dough and build up edges slightly. Bake at 400° for 8 minutes.
Meanwhile, in a nonstick skillet coated with cooking spray, saute the mushrooms, onion, broccoli, green pepper and spinach until crisp-tender.
Spread spaghetti sauce over crust. Top with sauteed vegetables, tomatoes and cheese. Bake for 15-20 minutes or until crust is golden brown and cheese is melted. Let stand for 10 minutes before serving.