Prepare. Start by placing your skillet into your oven and preheating the oven with the skillet to 425°f. Also, have a safe location to place a hot skillet on when you take it out of the oven to work. Some folks like to use a thick wooden cutting board or trivet for example.
Dry Ingredients. In a large mixing bowl, use a whisk to combine together the flour, cornmeal, baking powder, baking soda, and salt.
Wet Ingredients In a medium bowl, use a clean whisk or fork to combine together the buttermilk, eggs, and melted butter.
Combine. Add the wet ingredients from the last bowl to the large mixing bowl and use a rubber spatula or similar item to mix the ingredients until just combined.
Transfer. Very carefully take the warmed skillet out of your oven and place it on the safe location that you set out in the first step. Pour the oil over the skillet and swirl or move it around so the the skillet is fully coated with with the oil. Lastly, transfer your batter to the warm skillet, evenly spreading it out use the spatula or the backside of a spoon.
Bake. Carefully return the skillet to your oven and bake the cornbread until it is golden brown around the edges and the center appears to be cooked through.
Cool. Allow the bread to cool for a five to 10 minutes in the skillet before transferring it to a cooling rack or plate to fully cool.