- Preheat oven to 450 degrees. Coat the inside of a heavy black muffin tin or 10-inch cast-iron skillet with bacon fat and butter and heat pan in the oven for about 5 to 10 minutes.
- Meanwhile, sift dry ingredients. In a separate small bowl, beat egg and add milks. Pour egg mixture into dry ingredients and stir until just combined.
- Remove tin from oven when very hot and pour any excess fat into the cornmeal mixture, along with remaining butter and bacon fat. Stir until combined and pour into tin. Bake until golden and firm to the touch, about 20 minutes. Turn onto wire rack to cool slightly before serving.