Heat oven to 425. Spray a 9" x 13" baking pan w/ cooking spray.
In lg skillet, over high heat, add oil. Add sausage and mushrooms. Cokk, stirring for 4-5 mins. Stir in tomato sauce, oregano, garlic powder, salt and pepper. Cook until heated through.
Unroll pizza dough and press into bottom and 1/2 way up the sides of pan. Line bottom crust w/ 6 slices mozzarella cheese. Top w/ sausage mix. Bake, uncovered 12 min. Top w/ remaining slices of mozzarella cheese. Sprinkle w/ parmesan cheese. Bake 5 min, or until cheese melts.