Add the potatoes to a large bowl. Add the grated Parmesan cheese, garlic powder, garlic, oil, Italian seasoning, salt, and pepper, and toss gently until all the potatoes are evenly covered.

Spray the slow cooker generously with cooking spray. Add the prepared potatoes to the slow cooker. Cook on LOW for 2-4 hours or HIGH for 1-2 hours. Top with shredded Parmesan cheese. Turn off the slow cooker and let it sit with the lid on until the cheese melts.

Add water or broth to the Instant Pot. Add the prepared potatoes. Close the lid and seal the valve. Set to high pressure and cook for 3 minutes. When done, quick release the pressure. Top with shredded Parmesan cheese. Turn off the Instant Pot and let it sit with the lid on until the cheese melts.