In an 8x8 or 9x9 inch glass pan, melt ½ cup of butter in the microwave and spread it evenly up the sides of the pan.
Drain the whole kernel corn and add it to the prepared pan along with the creamed corn, sour cream, sugar, salt, and Jiffy corn muffin mix. Stir until well combined.
Place the pan in the oven and bake for 35-40 minutes, or until golden brown around the edges.
Let the casserole cool for a couple of minutes before serving warm.
Notes
Ensure ingredients are at room temperature.
Avoid overmixing to keep the casserole fluffy.
If the top browns too quickly, cover loosely with aluminum foil during the last 15 minutes of baking.