Spray a 6 quart crock pot with non stick spray; set aside.
Peel potatoes and slice 1/8" thick. Arrange a third of the potatoes in the bottom of the prepared crock pot.
Drizzle about a third of the cream evenly over the potatoes. Sprinkle a third of the garlic, minced onion, Parmesan, salt, and pepper over the potatoes. Repeat two more times.
Cover slow cooker. Cook potatoes on HIGH for 4-5 hours or until tender.
Sprinkle cheese on top of potatoes. Cook for about 5 more minutes or until cheese is melted. Serve hot.