Preheat oven to 350°F. Prepare a 9-by-13-inch (or equivalently sized) baking dish by brushing with some of the melted butter. Sprinkle a bit of the Parmesan cheese on the bottom of the dish in a thin layer, and tilt dish so that the bottom and sides get evenly coated with Parmesan.
Pour cream in a 4-quart saucepan and heat over medium-low until it begins to simmer. Stir in the corn, salt, and sugar until mixture begins to bubble.
In a small bowl, whisk flour into the remaining melted butter. Slowly blend this paste into the corn mixture and stir until thickened.
Pour corn mixture into prepared dish, spread into an even layer, and sprinkle with remaining Parmesan cheese. Bake for 25 to 30 minutes or until bubbly and golden brown.