Preheat oven to 350°F (175°C). Grease an 8x8-inch, 9x9-inch, or 2-quart baking dish with 1 tablespoon softened butter.
In a large mixing bowl, whisk together the melted unsalted butter, sour cream, lightly beaten eggs, honey, and fine sea salt until smooth and uniform.
Add the undrained cream-style sweet corn and the thoroughly drained whole kernel sweet corn. Stir to combine.
Sprinkle the dry cornbread mix over the corn mixture. Gently fold with a rubber spatula just until dry ingredients are moistened (do not overmix).
Spread the batter evenly into the prepared baking dish.
Bake uncovered at 350°F (175°C) for 45 to 55 minutes, until the top is deep golden brown and the edges are set and bubbly, with a slight, gentle jiggle in the very center.
Remove from the oven and let rest on a wire rack for 10 minutes to allow the custard to set before serving warm with scoops of honey butter!