Preheat oven to 350*F. With cooking spray, lightly grease a 2.5 qt. baking dish.
Bring a large pot of lightly salted water to a boil. Stir in pasta and cook for 8 - 10 minutes until al dente and drain.
In a large skillet, over medium heat, cook the Italian sausage and onion until sausage is evenly brown and onion is tender. Drain grease.
In a bowl, mix the pizza sauce, tomato sauce, and milk. Stir in the cooked sausage and onion, pepperoni, and Canadian bacon. Add the garlic powder and Italian seasoning. Gently mix in the cooked pasta until evenly coated. Transfer to baking dish.
Cover and bake for 30 minutes in the preheated oven. Remove cover, top with cheeses and continue baking for 15 minutes until the cheese is melted and bubbly. Remove from oven, sprinkle fresh parsley on top and serve.