Combine rolls and roll into a 9x13-inch rectangle. Cover with plastic wrap and let rest.
Brown ground beef and onion. Drain off fat. Blend in pizza sauce, garlic salt, and oregano. Spread in the bottom of a sprayed 9x13-inch pan. Sprinkle with mozzarella cheese.
Remove wrap from dough and place dough over meat mixture in pan to completely cover . Cut a small slit in the dough to vent steam. Sprinkle with Parmesan and bake at 350°F 25-30 minutes.