Preheat oven to 350°F and lightly grease a casserole dish.
In a large bowl, combine melted butter, corn, cream-style corn, sour cream, and Jiffy mix. Stir until smooth and well combined.
Pour the mixture into the prepared casserole dish and spread evenly.
Bake for about 45 minutes, or until the top is golden and a toothpick inserted in the center comes out clean.
Let it rest a few minutes before serving — it's best warm!
