1. Position an oven rack in the lowest setting; place a pizza stone on rack. Preheat oven to 500°.
2. Remove dough from refrigerator. Let stand, covered, for 30 minutes.
3. Combine mushrooms and next 4 ingredients (through onion) in a large bowl; drizzle with 1 1/2 tablespoons oil. Toss. Arrange vegetables on a jelly-roll pan. Bake at 500° for 15 minutes.
4. Punch dough down. Sprinkle a lightly floured baking sheet with cornmeal; roll dough out to 15-inch circle on prepared baking sheet. Brush dough with 1 teaspoon oil. Spread sauce over dough, leaving a 1/2-inch border. Sprinkle 1/2 cup mozzarella over sauce; top with vegetables. Sprinkle 1/2 cup mozzarella and red pepper over zucchini mixture. Dollop with ricotta. Slide pizza onto preheated pizza stone. Bake at 500° for 11 minutes or until crust is golden. Sprinkle with basil.