1. Preheat oven to 200ºF and preheat waffle iron. In a large bowl, whisk together flour, cornmeal, baking powder, salt and sugar. In a glass measuring cup, whisk together milk, egg and butter. Pour milk mixture into flour mixture and stir until just combined. Fold in corn and cheese.
2. Mist waffle iron with cooking spray. Pour batter onto grates and spread to edges with a spatula. Cook until waffles are golden, 5 to 7 minutes. Transfer to a plate, loosely cover with foil and keep warm in oven. Repeat with remaining batter, misting grates with cooking spray before each new batch.