1. Preheat the oven to 350°F and grease a 9×13-inch baking dish.2. Scrub the potatoes and then slice with skins on into ¼-inch thick slices.3. In a large mixing bowl, stir together the mayonnaise, sour cream, salt, pepper, onion and 1 cup of the cheddar cheese. Carefully fold in the potato slices, pour into the prepared baking dish and spread evenly in the pan.4. Top with remaining cup of cheddar cheese and then sprinkle the bacon all over.5. Bake for 1 hour or until bubbly and beginning to brown.