Start by preheating your oven to 350 degrees Fahrenheit. While the oven is warming up, grease a 9 by 13 inch baking dish with a light coating of butter or non-stick cooking spray to ensure nothing sticks to the sides during the baking process.
In a large mixing bowl, combine the frozen corn kernels, cubes of cream cheese, and the slices of butter. You do not need to melt the butter or soften the cream cheese completely beforehand, as they will melt into the corn while baking. Stir in the sugar, salt, and black pepper until the corn is evenly coated with the seasonings.
Spread the corn mixture evenly into your prepared baking dish. Use a spatula to level the top so that the heat distributes evenly. At this stage, the cream cheese and butter will still look like distinct chunks, but they will transform into a creamy sauce in the oven.
Place the dish in the center rack of the oven and bake for 30 minutes. After 30 minutes, remove the dish briefly to stir the ingredients together, ensuring the melted cheese and butter form a smooth sauce. Sprinkle the shredded cheddar cheese over the top and return it to the oven for another 10 minutes or until the cheese is bubbly and slightly golden.
Once the casserole is finished baking, remove it from the oven and let it sit for about 5 minutes. This resting period allows the sauce to thicken slightly. Sprinkle with fresh chives before serving to add a pop of color and a fresh finish to your Christmas spread.
