Coat a 12-in. pizza pan with cooking spray; sprinkle with cornmeal. Prepare pizza dough according to package directions. With floured hands, press dough onto prepared pan. Bake at 450° for 7-10 minutes or until lightly browned.
Spread taco sauce over crust to within 1 in. of edges. Top with tomatoes, beans, corn, chilies, onions and cheese.
Bake for 10-15 minutes or until cheese is melted and crust is golden brown. Serve with sour cream if desired.