Grill-Baked Skillet Cornbread

For Heating a Charcoal Grill: Open bottom vent completely. Light chimney starter mounded with charcoal briquettes (7 quarts). Once top coals are partially covered with ash, pour into a steeply banked pile against 1 side of the grill. Set cooking grate in place, cover, and open lid vent. Heat until grill is hot (500°F; 260°C), about 5 minutes. Serious Eats / Lorena Masso For Heating a Gas Grill: Turn all burners to high, cover, and heat grill until hot (500°F; 260°C), about 15 minutes. Leave primary burner on high and turn off other burner(s). (see notes) Clean and oil cooking grate. Set corn and poblanos over hotter side of grill (close grill lid if using gas) and cook, turning as needed, until poblanos are blistered and charred in spots, and corn is charred all over, 7 to 10 minutes. Transfer poblanos and corn to cutting board; let cool slightly. (If using a charcoal grill, use tongs to carefully remove cooking grate and add 1 quart of unlit coals to the lit coals in a steeply banked pile, then return cooking grate.) Serious Eats / Lorena Masso Stem, seed, and chop poblanos. Cut kernels from corn; you should have about 1 1/2 cups kernels. Serious Eats / Lorena Masso Place a 10-inch cast-iron skillet on the hotter side of the grill. Add cornmeal and toast, stirring frequently, until fragrant, about 5 minutes. Using grill gloves, remove skillet from grill and transfer toasted cornmeal to a large bowl. Whisk sugar, baking powder, baking soda, and salt into cornmeal. Whisk in sour cream, milk, oil, 1/4 cup melted butter, and eggs until combined. Stir in chopped poblanos and corn kernels. Serious Eats / Lorena Masso Brush empty skillet with remaining 1 tablespoon melted butter. Scrape batter into skillet and smooth top. Place skillet on the cooler side of the grill, cover grill, and bake, rotating skillet halfway through baking, until top is golden brown and toothpick inserted into center comes out clean, 20 to 35 minutes. (For a gar grill, adjust primary burner as needed to maintain grill temperature between 400 to 225°F (200 to 230°C); if using 3-or-more-burner grill, adjust primary burner and second burner, leaving other burners off.Transfer skillet to wire rack and let cornbread cool for at least 30 minutes. Slice and serve. Serious Eats / Lorena Masso