Thaw potatoes in large mixing bowl. Cook bacon well done to a crisp, crumble and set aside.
In separate bowl mix - soup, mayonnaise, sour cream, salt, pepper, and onion.
Blend soup mixture into thawed potatoes until coated. Add cheese and bacon bits and combine well.
Place potato mixture into greased 9x13 glass baking dish. Bake for 30 mins at 350°.
Pull from oven and add corn flakes on top, drizzle melted butter over corn flakes, and bake casserole for an additional 20-30 mins until hot. If the corn flakes are not browned really well and the casserole is not bubbling, you can leave it in up to an extra 10 minutes, watching carefully to avoid burning.