Preheat oven to 425°F.
Mix the egg and buttermilk together. Add the cornmeal, baking powder, baking soda and salt. Add corn. Mix with large spoon or whisk.
Put butter in well-seasoned 10-inch cast iron skillet over medium to high heat.
Just as the butter is about to start smoking, pour it into the cornmeal mixture, stirring as you pour (if you can manage it). Leave enough in the skillet to coat the bottom and sides.
Stir the butter into the cornmeal mixture and then pour the entire mixture into the buttered skillet.
Place skillet on middle rack of oven; bake until cornbread is springy in the middle, browned and pulling away from the skillet on the sides (about 15-20 minutes).
Remove from oven and invert skillet over serving plate. If cornbread does not drop easily, you may need to run an icing spatula or even a flexible metal egg-turner around/under it so it comes loose.
Serve hot, with plenty of butter. Or margarine, if you insist.
by The Savvy Kitchen