First, preheat your oven to 375°F and place your skillet or baking dish in the oven to get nice and hot. I like to use a 12 inch cast-iron skillet. (Adding the cold batter to the hot pan will help you get crispy edges and a nice crust on your cornbread. )
Next, melt your butter and if you do not have buttermilk, prepare your "faux buttermilk" now by combining 1 cup of milk with 2 tablespoons of distilled white vinegar.
Combine all of your dry ingredients in a large bowl and mix until everything is evenly distributed - flour, cornmeal, sugar, baking soda, baking powder, and salt.
The next step is to whisk the eggs into your buttermilk or "faux buttermilk" using a fork. Make sure it is combined well and the eggs are whisked and broken up nicely.
Add the egg/buttermilk mixture and your melted butter to the dry ingredients. (Make sure that the butter has cooled off enough so that your eggs don't scramble/curdle.)
Fold gently, until the wet and dry ingredients are just combined. If you over-mix, your batter won't be able to rise and your cornbread will be flat.
Once mixed, carefully remove your hot skillet from the oven. Coat the skillet with butter, bacon grease, or a nonstick spray. (Don't use spray on cast-iron!)
Pour your batter into the hot skillet. It's okay if it makes sizzling sounds - that's what we want - and place the skillet back in the oven.
Bake for about 30 - 35 minutes at 375°F.
Cornbread is done once the edges pull away from the pan and the top makes a knocking sound when you tap it. If you poke the cornbread, it should not sink in. Cornbread is pretty stiff when it is done, but it has a slight spring when you touch it.
Serve your cornbread immediately or store in an air-tight container once cooled.