How to Make It
Preheat the oven to 350°. Generously grease a 9-inch-square baking dish.
In a large bowl, whisk the sour cream with the 6 tablespoons of melted butter, the egg, salt and pepper. Whisk in the corn muffin mix until combined. Using a rubber spatula, fold in the thawed corn, canned corn, cheddar and scallions. Spread the casserole mixture in the prepared dish and bake for about 1 hour, until puffed and golden brown. Serve.