Preheat your oven to 350°F (175°C). Grease a 9×13 inch or a 2-quart baking dish with butter or non-stick spray.
Step 2: Create the Creamy Base
In a large microwave-safe bowl, combine the cubed cream cheese and ¼ cup of the melted butter. Heat in the microwave in 30-second bursts, stirring in between, until the cream cheese is melted and the mixture is smooth.
Whisk in the remaining ¼ cup of melted butter, sour cream, and beaten eggs until well combined.
Step 3: Combine All Ingredients
To the creamy base, add the corn, ½ cup of the shredded cheddar cheese, diced green chiles (if using), sugar, and garlic powder. Season with a good pinch of salt and pepper. Stir until everything is evenly coated.
Sprinkle the entire box of corn muffin mix over the top. Gently fold it in just until combined. Do not overmix.
Step 4: Assemble and Top
Pour the mixture into the prepared baking dish and spread it into an even layer.
Sprinkle the remaining ½ cup of cheddar cheese evenly over the top.
For a crispy topping, sprinkle the crushed crackers or the reserved corn muffin mix/butter mixture over the cheese.
Step 5: Bake to Golden-Bubbly Perfection
Bake for 40-50 minutes, or until the casserole is set around the edges, the top is deep golden brown, and the center only jiggles slightly.
For an extra-golden top, you can broil for the last 1-2 minutes (watch closely!).
Step 6: Rest and Serve
Let the casserole rest for 10 minutes before serving. This allows it to set up for cleaner slices and for the flavors to settle.
Garnish with chopped fresh chives or parsley for a pop of color and freshness.
