Preheat oven to 375°F and grease a 9x13-inch baking dish with butter or cooking spray.

Slice 2 pounds of Yukon Gold or Russet potatoes into ¼-inch thick rounds.

Mix heavy cream, sour cream, garlic powder, salt, and pepper in a large bowl until smooth and velvety.

Layer half of the potatoes, followed by half of the diced ham and one-third of the shredded cheddar. Repeat, ending with a final cheese layer on top.

Bake covered with foil at 375°F for 30 minutes.

Uncover the dish, sprinkle remaining cheese and breadcrumbs, then bake uncovered for 10 minutes.

Rest the casserole for 5 minutes before slicing.