Use fresh not frozen hash browns. The brand is called Simply Potatoes and I find them in the dairy section. I used frozen one year and no one ate it. It's very rich but people do like it. My mother used to make it and instead of corn flakes, she topped it with 1 cup of plain crushed Lays potatoes chips BUT I am rating this based on the exact recipe above, not my mother's version.

Does anyone know if this casserole can be made a day ahead????

Far too much butter. Mom made it with half that amount and it tastes just as good. :)