Preheat the oven to 350°F and liberally grease a 9x13-inch baking pan with cooking spray.
In a large mixing bowl, mix together the corn, creamed corn, cornmeal, flour, sugar, baking powder, salt, vegan sour cream, and vegan butter just until all of the ingredients are well incorporated.
Spread the batter into the baking dish and bake for 50 minutes or until a toothpick inserted into the center comes out clean with a couple of crumbles on it.
Notes
To store:Wrap the baking dish tightly with plastic wrap or aluminum foil, or transfer the leftover corn soufflé to an airtight container. Refrigerate for up to 3-4 days. To reheat, simply cover the dish with foil and warm it in a preheated oven at 350°F until it's heated through. Alternatively, individual portions can be microwaved until warm.To freeze: Corn soufflé can be frozen for up to 2 months, either wrapped in the baking dish or in an airtight container. To serve, thaw overnight in the refrigerator, then reheat according to the instructions above.