Combine the first three ingredients in a bowl. In a second bowl, beat the egg, add the buttermilk, and whisk in the bacon fat and butter.
Pour the dry ingredients into the wet ones and mix until just combined. Don't worry about small lumps.
Pour the batter into the preheated skillet and return it to the oven at 450 degrees. Bake for twenty minutes, or until the middle of the top begins to brown lightly.
