Preheat oven to 450F. Place a well-seasoned (oiled) cast-iron skillet in the oven while it is warming. You want the skillet to be very hot.
In a large bowl, mix together all ingredients.
One the oven has heated and the skillet is hot, pour batter into the cast-iron skillet. It should sizzle upon hitting the oil, which will help the crust be very crisp.
Bake for roughly 20 minutes. Check doneness with a toothpick in the center; if it comes out clean, it is done.
Enjoy!
Notes
Be sure to place your skillet in the oven as it is pre-heating. You want your skillet to be hot + sizzle upon the batter pouring in. This will help you achieve the perfect crust!
To make the cornbread spicier, sub chiles for jalapeños or serrano peppers.
To check the doneness of the cornbread, insert a toothpick into the center. If it comes out clean, it is done.