Preheat oven to 400°F. Spray 13x9-inch glass baking dish with cooking spray; set aside.
Spray large skillet with cooking spray; heat over medium-high heat. Add beef, sausage and onion; cook 7 minutes or until beef is crumbled and no longer pink, stirring occasionally. Add tomato sauce; stir to combine.
Transfer meat mixture to baking dish; top with pepperoni slices and cheese. Place pizza dough on top of cheese, folding extra dough over to create an edge. Bake 12 to 15 minutes or until mixture is bubbly and crust is golden brown.