Preheat your oven to 350°F (175°C).

In a large mixing bowl, combine the whole kernel corn, creamed corn, sour cream, and melted butter.

Add the corn muffin mix, shredded cheddar cheese, salt, and black pepper to the bowl, stirring until just combined.

Pour the mixture into a greased 9x13-inch baking dish.

Bake in the preheated oven for 45-50 minutes, or until golden and set.

Let the casserole cool for a few minutes before serving.