Preheat the oven to 425° F.
Cook the bacon in a 9-inch cast iron skillet; transfer to a plate lined with paper towel and drain. Crumble when cool.
Brush the inside surface—sides and bottom—with the bacon fat and drain off all but 1 tablespoon.
Combine the flour, cornmeal, sugar, baking powder, baking soda and salt in a bowl.
Lightly beat the eggs in a second bowl; stir in the buttermilk and melted butter. Stir the wet mixture into the dry until just combined; stir in 1 cup of the cheese, scallions and crumbled bacon and transfer to the skillet. Bake until the cornbread is golden around the edges and a toothpick inserted in the center comes clean, about 20 minutes. Sprinkle with the remaining 1/4 cup of cheese and bake until the cheese is melted, another 4-5 minutes. Cool at least 10 minutes before slicing.