Preheat the oven to 350°F. Grease a 13x9-inch baking pan or 10-inch ovenproof skillet generously with unsalted butter.
In a large bowl, whisk together the flour, cornmeal, sugar, baking powder and 1/2 teaspoon kosher salt.
In a separate medium bowl, whisk together the melted butter, sour cream, eggs, creamed corn and corn kernels. Add the wet ingredients to the dry and mix just until combined.
Scrape the batter into the prepared baking pan then bake, uncovered, until a toothpick inserted comes out clean, 35 to 40 minutes.
Let cool slightly then serve.