Preheat your oven to 350°F (175°C).

Grease a 9x13-inch baking dish with 1 tablespoon of butter.

In a large mixing bowl, combine softened cream cheese, sour cream, and milk, whip until smooth.

Stir in sweet corn, shredded cheddar cheese, grated Parmesan cheese, white sugar, all-purpose flour, garlic powder, onion powder, and season with salt and pepper.

Pour the mixture into the greased baking dish evenly.

Bake in the preheated oven for 45-50 minutes until golden brown.

Let the casserole cool for 5-10 minutes before serving.

Garnish with chopped green onions or parsley before serving.