Adapted from Sara Foster's Southern Kitchen
2 tablespoons bacon grease or olive oil
1-1/2 cups yellow cornmeal
1/2 cup all-purpose flour
1/4 cup sugar
2 teaspoons baking powder
2 teaspoons salt, plus some kosher salt for sprinkling on top
1 teaspoon freshly-ground black pepper, plus more for sprinkling on top
1/2 teaspoon baking soda
2 cups well-shaken buttermilk
2 large eggs, lightly beaten
2 tablespoons unsalted butter, melted
Preheat oven to 425 degrees. Coat a 9" or 10" cast-iron skillet with the bacon grease and place it in the oven to heat.
Whisk together the cornmeal, flour, sugar, baking powder, salt, pepper, and baking soda in a large bowl. Add the buttermilk, eggs, and butter and stir until just combined (batter should be lumpy).
Pour the batter into the hot skillet and sprinkle the top with kosher salt and pepper. Bake until the top is golden brown and a tester comes out of the center clean, about 25 minutes.
Remove from the oven and turn cornbread out of skillet. Slice into wedges and serve warm.