Step 1

Preheat oven to 375°F. Coat a 13- x 9-inch baking dish with cooking spray. Whisk together heavy cream and flour; set aside.

Step 2

Arrange 2 even layers of potato slices in prepared dish; sprinkle with 1/2 teaspoon salt and 1/4 teaspoon pepper. Top with one-third of the cheese slices (6 to 8 slices), overlapping to fit; sprinkle with 1/2 cup ham. Pour about 1/2 cup of the cream mixture over the layers. Repeat process 2 more times with remaining ingredients, ending with a fourth layer of potatoes, salt, and pepper. Pour remaining cream mixture evenly over potatoes. Gently wiggle the dish to be sure cream settles into all areas.

Step 3

Bake in preheated oven 1 hour. If potatoes begin to brown too much, loosely cover dish with aluminum foil, venting to allow steam to escape. Bake an additional 30 minutes, partially covered, until potatoes are very tender and top of casserole is golden brown. Let stand 15 minutes before serving.