Heat the oven to 425°F with a 10-inch cast-iron skillet inside for 10 minutes.
Whisk the cornmeal, flour, baking powder, baking soda and salt in a large bowl.
Whisk the buttermilk and eggs together and stir them into the dry mixture just until combined.
Carefully add the bacon drippings to the hot skillet, swirl to coat, and pour all but 1 tablespoon of the fat into the batter.
Stir once, pour the batter into the hissing skillet, and bake for 22 to 25 minutes until the edges pull away and the center springs back.
Cool for 10 minutes before cutting into 10 wedges.