In a skillet over medium heat, cook the ground beef until browned and fully cooked (about 6–7 minutes). Drain any excess grease.
Add the cooked beef to your slow cooker. Stir in the ranch seasoning, corn, Alfredo sauce, garlic powder, black pepper, and milk or cream if using.
Cover and cook on LOW for 3–4 hours or HIGH for 1.5–2 hours, until hot and bubbly.
About 20 minutes before serving, boil the pasta in salted water according to package instructions. Drain well.
Stir the cooked pasta into the slow cooker along with the mozzarella and Parmesan cheese. Mix until melted and creamy.
Serve warm, topped with parsley or chives if desired.
