Preheat oven to 425°. Heat a 12-inch cast-iron skillet over medium-high heat. Add halved jalapeños to skillet. Cook until lightly charred, about 2 minutes per side. Remove from skillet.
Add oil to skillet, and place skillet in oven until oil is very hot, about 8 minutes.
In a large bowl, whisk together cornmeal, flour, chopped jalapeño, baking powder, and salt. In another large bowl, whisk together buttermilk, melted butter, and eggs. Make a well in center of cornmeal mixture, and stir in buttermilk mixture just until combined. Stir in goat cheese. Carefully pour batter into hot skillet. Sprinkle with Cheddar; top with charred jalapeños, cut side up.
Bake until golden brown and a wooden pick inserted in center comes out clean, about 35 minutes. Serve immediately.
Recipe by Southern Cast Iron at https://southerncastiron.com/jalapeno-goat-cheese-cornbread/