Preheat oven to 400°F.
Bring a large pot of salted water to a boil. Add pasta and cook 1 minute less than the package calls for al dente. Drain and set aside.
In a large skillet or pot over medium high heat, add Italian sausage and ground beef. Crumble and cook until browned and cooked through (about 7-10 minutes). Drain excess fat if necessary. Season with a seasoning salt blend or salt and black pepper.
In a separate pan, heat olive oil over medium heat. Add the sliced mushrooms and sauté until they are tender and browned (about 5-7 minutes). Season with a seasoning salt blend or salt and black pepper.
In the pan with the cooked meat, add the sautéed mushrooms, pepperoni, salami, black olives, and marinara sauce. Add ¾ cup water to the pasta sauce jar. Close, shake, then add to the pan. Stir to combine and let it simmer on low-medium heat for about 5 minutes.
In a large bowl, combine the cooked and drained pasta, meat sauce, and ½ cup of the mozzarella cheese. Stir until the pasta is well coated.
Pour the mixture into a 13x9-inch baking dish. Sprinkle the remaining mozzarella cheese on top of the pasta.
Bake 8-10 minutes or until the cheese starts to turn golden brown. Carefully remove from the oven. If desired, sprinkle with shredded Parmesan cheese and/or fresh basil before serving.
Alternatively, you can opt to serve this dish straight from the stovetop. Make sure the pan used to make the meaty sauce is large enough to fold in the cooked and drained pasta and ½ cup of the mozzarella cheese. Add the remaining cheese to the top, cover with a lid, and allow the mixture to cook until the cheese melts.