How to Make It
Preheat oven to 350°F. Stir together flour, sugar, baking powder, and salt in a small bowl until blended. Whisk together eggs, cream, and melted butter in a medium bowl until blended.
Heat canola oil in a large skillet over medium-high. Add corn and onion, and cook, stirring often, until onion is softened, about 5 minutes. Remove from heat, and let cool slightly, about 5 minutes. Stir in cheeses and parsley.
Stir flour mixture and corn mixture into egg mixture. Spoon into a 13- x 9-inch (3-quart) baking dish, and bake in preheated oven until set and golden brown, about 40 minutes. Let stand 5 minutes before serving.
Make it ahead: Bake as directed, let cool, and then cover and chill up to 2 days. Reheat covered with foil.