1. Spray a 6-quart or larger slow cooker with cooking spray and set aside.

2. Cook the pasta according to package directions to al dente (usually about 1-2 minutes less than package instructions). Drain well and set aside.

3. While the pasta cooks, place a large skillet over medium-high heat. Add the ground beef, Italian sausage, and diced onion. Break the meat into crumbles and cook, stirring occasionally, until the onions are softened and the meat is no longer pink.

4. Lower the heat to medium-low. Add the chopped pepperoni and minced garlic to the pan. Stir well and cook for 5 minutes, stirring occasionally. Drain any excess grease.

5. Transfer the drained meat mixture to a large bowl. Add the pizza sauce and Italian seasoning, stirring to combine. Then, add the cooked pasta and mix until everything is well coated.

6. Add half of the pasta mixture to the slow cooker. Top with half of the mozzarella cheese. Add the remaining pasta mixture on top, then finish with the remaining cheese.

7. Cover and cook on low for 3-4 hours until heated through and the cheese is melted and bubbly.

8. Garnish with fresh parsley, if desired, and serve hot.