Preheat oven to 350°F and grease a 9x13-inch baking dish.

In a large bowl, combine whole kernel corn, creamed corn, corn muffin mix, sour cream, and melted butter. Stir gently until just mixed.

Pour the mixture into the prepared baking dish and spread it evenly.

Bake for 45–50 minutes until golden brown on top and the center is set.

Let rest for 5–10 minutes before serving.