In a large bowl, combine the frozen hash browns, Cream of Chicken Soup Substitute, sour cream, ½ cup melted butter, chopped onion, salt, and pepper. Mix well until everything is evenly blended.
Add in 2 cups of the shredded sharp cheddar and combine until incorporated.
Take a well-greased 9×13 inch casserole dish. Pour the potato mixture into the dish, spreading it evenly.
Sprinkle the remaining shredded cheddar on top.
If desired, mix in the diced jalapeños with the potato mixture before transferring it to the casserole dish.
Crush the corn flakes in a separate bowl, then combine them with the remaining melted butter. Mix until well coated.
Sprinkle this mixture evenly over the top of the casserole.
Preheat your oven to 350 degrees F. Bake the casserole for about 50 minutes or until bubbling and the topping is golden brown.
Remove and let sit for a few minutes before serving.
Notes
Feel free to customize with different cheeses or add cooked beef bacon for more flavor.
Leftovers can be stored in an airtight container and reheated well.