Cube potatoes into bite sized pieces, leaving the skin on.
Put potatoes in a large sauce pan and cover with cold water. Add some salt and bring to a boil.
Cook for about 10 minutes or until tender.
Preheat oven to 350°F
Put half of the potatoes in a large casserole or 9×13 pan (you can halve the recipe and make it in an 8-9-inch pan or two quart casserole). Sprinkle with half of the cheese. Repeat with remaining potatoes and cheese.
Distribute bacon over the cheese and potatoes. Sprinkle with salt and pepper. Drizzle the butter over the top.
Bake for 10-15 minutes. Casserole is done when cheese is completely melted.