Preheat the oven to 350 degrees F (175 degrees C). Grease a 9-inch square baking pan.
Stir together whole kernel corn, cream-style corn, muffin mix, sour cream, melted butter, jalapeño peppers, and salt in a large bowl until combined. Pour batter into the prepared baking pan.
Bake in the preheated oven until a toothpick inserted into the center comes out clean, 45 to 60 minutes.