Stir together first 10 ingredients in a bowl; stir in jalapeño pepper, if desired.
Coat bottom and sides of a 9-inch cast-iron skillet with bacon drippings. Heat in a 450° oven 5 minutes. Pour cornbread batter into hot skillet.
Bake at 450° for 20 to 25 minutes or until cornbread is lightly browned.