Heat oven to 400°F. Spray 15x10x1-inch pan with cooking spray. Unroll dough; place in pan. Starting at center, press out dough to edge of pan.
Drizzle 3 tablespoons of the dressing over dough. Top with tomatoes, olives, onion, roasted peppers and cheese.
Bake 20 to 22 minutes or until crust is golden brown. Drizzle with remaining 1 tablespoon dressing. Sprinkle with oregano. Cut into 6 rows by 4 rows.