Prep and Mix Dry Ingredients. Preheat your oven to 350°F and grease an 11" x 8" ceramic baking dish. In a large mixing bowl, whisk together the gluten-free flour, gluten-free cornmeal, granulated sugar, baking powder, and salt until well combined.
Combine the Wet Ingredients. In a medium-sized bowl, whisk together the melted butter, sour cream, and eggs. Once smooth, stir in the drained whole kernel corn and creamed corn until fully incorporated.
Combine the Wet and Dry Ingredients. Pour the wet mixture into the bowl with the dry ingredients. Using a rubber spatula, gently fold everything together until just combined.
Combine the Wet and Dry Ingredients. Pour the wet mixture into the bowl with the dry ingredients. Using a rubber spatula, gently fold everything together until just combined.
Bake and Serve. Place the casserole in the preheated oven and bake uncovered for 45–50 minutes. You’ll know it’s ready when the edges are a beautiful golden brown, and the center is fully set. Remove from the oven and let the casserole sit for 10 minutes before serving; this allows the texture to firm up perfectly. Serve warm and enjoy!
Notes
Dairy-Free Version: For a dairy-free version, substitute the butter with a plant-based version, and the sour cream with your favorite unsweetened yogurt.