Preheat the oven to 375°F (190°C). Lightly grease a 9x13-inch baking dish and set aside.
Heat a large skillet over medium heat. Add ½ lb ground beef and ½ lb Italian sausage. Break the meat apart and cook until fully browned. Drain excess fat from the skillet.
Stir ½ cup pepperoni slices and ½ cup crumbled cooked bacon into the skillet with the browned meat. Let everything warm through for about 1 minute.
Add 2 cups pizza sauce, 1 tsp Italian seasoning, ½ tsp garlic powder, ¼ tsp black pepper, and salt to taste. Stir to combine and let the mixture simmer for 2 to 3 minutes.
In a large bowl, combine the 8 oz cooked and drained pasta, the meat sauce mixture, and 1 cup of the shredded mozzarella. Stir until evenly mixed.
Spread the pasta and meat mixture evenly into the prepared 9x13-inch baking dish.
Sprinkle the remaining 1 cup of mozzarella, ½ cup cheddar or provolone (if using), and any optional toppings like ½ cup sliced black olives or ½ cup sliced mushrooms evenly over the top.
Cover the dish loosely with foil and bake at 375°F for 15 minutes. Remove the foil and bake for an additional 10 to 15 minutes, until the cheese is fully melted, bubbly, and lightly golden on top.
Remove from the oven and let the casserole rest for 5 minutes before serving so it holds together when scooped.