Pour drippings or oil into an 9-inch square baking pan.
Heat pan in a 450 degree oven until oil is smoking hot.
While pan is heating, mix dry ingredients and any of the optional ingredients in medium-sized bowl.
Beat egg into buttermilk.
Add liquids to dry mixture, just until blended.
Do not overmix!
Carefully remove the smoking pan from oven and pour cornbread batter into pan. If the oil is properly hot, then the batter will sizzle as it hits the oil. (This sizzle is what makes a nice, crunchy bottom crust.)
Bake for 15-20 minutes, or until the top crust is golden brown.
Cut into wedges. Serve with butter or margarine.
Note 1: The batter will begin to rise as soon as the liquid and dry ingredients are mixed, so mix them right before you remove the hot pan from the oven.
Note 2: If you use a 10" round cast-iron skillet instead of the 9" baking pan, you should double the recipe without doubling the oil. If you don't double the recipe for the 10" skillet, your cornbread will be very thin.