Cornbread is almost a religion in the South. I've developed this recipe over the years. It's for a unique style called "cracklin' cornbread," which is a cornbread where any sort of ham or bacon, or even sausage, is cooked until the fat is rendered and the crispy cooked pork is put into cornbread.
Preheat the oven to 450 degrees F. Heat a cast-iron skillet over low heat until warmed through. Meanwhile, grind or cut the bacon into a small dice. Spread over pan evenly. Cook over medium-low heat, stirring frequently so that it doesn't burn, until the fat is rendered and the bits of bacon are crispy, 4–5 minutes. Drain the bacon in a strainer, reserving the fat to use in the recipe. (You will need 5 tablespoons.) Place skillet into the preheated oven to heat.
In a mixing bowl, whisk together the buttermilk, eggs, and salt. Slowly whisk in 3 tablespoons of the bacon fat. In a separate bowl, combine the cornmeal, salt, baking soda, baking powder, and bacon bits. Stir the dry ingredients into the wet ingredients, just to combine.
Move the skillet from the oven to the stove, placing it over low heat to keep it hot. Add 2 tablespoons of the reserved bacon fat to the skillet and swirl to coat the bottom. Pour the batter into the center of the skillet, distributing it evenly. It should sizzle. Cook on the stove over medium heat until the edge is golden and pulling away from the pan, 1–2 minutes.
Bake the cornbread until a toothpick placed in the center comes away clean, about 20–30 minutes. Optional: Rub a bit of lard on top of the finished cornbread and broil until golden and sizzling (less than one minute).
Serve in the skillet or flip out of the pan onto a plate. Slice into wedges and serve hot.