Place the hatch chiles on the grates of your gas range and turn the heat to high. Rotate the chiles until they’re evenly charred on all sides. Immediately transfer them to a cutting board and using the blade of a knife, scrape the charred skins off of the peppers. Slice open the peppers and discard the seeds. Dice the softened peppers and set them aside. Beware that these are spicy so don’t rub your eyes!
Preheat the oven to 375 degrees F. I used four 4-inch cast iron skillets but a 10-inch would work just as well. Grease whatever skillet(s) you’re using with cooking spray or oil.
In a large bowl, whisk together the corn flour (or cornmeal if using), all-purpose flour, salt and baking soda.
In a medium skillet, set over medium heat, melt the butter. Once melted turn off the heat and stir in the sugar. Pour in the buttermilk and crack in the eggs and beat until well combined. Pour the wet ingredients into the dry and stir. The batter will resemble a very wet pancake batter. A few lumps are totally fine and good! Fold in the chopped hatch chiles. Pour the batter into the prepared cast iron skillets or cast iron skillet.
Transfer to the oven and bake for 17 to 22 minutes, or until a toothpick inserted in the center comes out clean. A heads up: if you’re using a big cast iron skillet, the baking time will be longer, about 30 to 35 minutes. Slice it up and serve with butter and a drizzling of maple syrup.