Place chicken breasts on bottom of slow cooker.
In a small bowl, combine the mayonnaise, Parmesan, seasoning salt, black pepper, and garlic powder.
Spread mixture evenly on top of chicken breasts.
Place lid on slow cooker and cook on high for 4 hours, or low for about 6 hours.
Once cooked, remove from slow cooker and serve over zoodles (zucchini noodles) or cooked pasta.