Add frozen corn, heavy cream, salt, sugar, pepper, and butter to a large pot.
In a small bowl or measuring cup, whisk together the 1/2 cup milk and flour (this will help thicken the cream). Stir into the corn mixture and cook over medium heat, stirring often so the cream doesn't burn, until the mixture is thickened and the corn is cooked through. If you don't cook it until it's thickened, it will be runny (although it will still taste wonderful).
Remove from heat and stir in 1/4 cup Parmesan cheese.
Notes
If you are taking the cream to a gathering, get it nice and thick before you keep it warm in a slow cooker. It can easily be doubled or tripled for a crowd!