In a medium-sized bowl, pour 2/3 to 3/4 (approximate) of the buttermilk over the cornbread and let soak for 15 minutes.
Preheat oven to 350 degrees while the cornbread is soaking. Put your cast iron frying pan in the oven to warm.
Sift the dry ingredients (flour, baking powder, salt, baking soda) into a large bowl, sufficient to hold the dry and wet ingredients
In a small bowl, lightly beat the eggs; add the vegetable oil and mix.
Remove the cast iron frying pan from the oven.
Add corn to the wet ingredients. If you are using bacon and/or cheese, add now. Stir.
Butter or grease the (large) cast iron frying pan (make sure you coat the sides) and add about a T of oil to the bottom of the pan. I use bacon grease.
Pour the cornmeal (wet) mixture over the flour mixture. Combine, being careful not to over stir; you’ll see bubbling from the baking soda. Add enough of the remaining buttermilk to make the mixture pourable.
Pour the mixture into the frying pan.
Bake 25-30 minutes or until golden brown.
Cornbread is a variation on my mother’s as well as Alton Brown’s recipe in I’m Just Here for More Food. Also, see SpoonForkBacon for savory butters.