Heat the oven to 400 degrees. Place a 10-inch cast iron skillet on the center rack of the oven.

While the oven is heating, whisk together the cornmeal, flour, baking powder and salt in a large bowl. In a medium bowl, whisk together the buttermilk, corn, eggs and jalapeños. Slowly whisk in the butter. Whisk the buttermilk mixture into the cornmeal mixture until just combined. Add the bacon grease to the hot cast iron skillet and swirl to make sure entire bottom of the skillet is coated. Pour the batter into the hot skillet, smoothing the top into an even layer.

While the oven is heating, whisk together the cornmeal, flour, baking powder and salt in a large bowl. In a medium bowl, whisk together the buttermilk

. Bake until the cornbread is golden brown and a toothpick inserted in the center comes out clean, 25 to 30 minutes. Let cool for 10 minutes, slice into wedges and serve hot.