Preheat oven to 350 degrees F. Mix potatoes, soup, and sour cream in a bowl.
Place mixture in casserole dish; use Pam so it doesn't stick. Pour cheese on top. (Sometimes I use more or less than 1 cup...depending on mood.) Drizzle butter over casserole. (I've cut this down to 1/2 stick and it works just as well.) Add corn flakes on top.