01 - Preheat oven to 375°F. Grease a 9x13-inch baking dish thoroughly.
02 - Heat olive oil in a large skillet over medium heat. Add diced onion and minced garlic, sauté until aromatic and softened, about 3 minutes.
03 - Add ground beef or plant-based alternative to the skillet, cook until browned while breaking into small pieces. If necessary, drain excess fat.
04 - Stir in kidney beans, black beans, diced tomatoes, tomato sauce, chili powder, cumin, smoked paprika, salt, black pepper, and frozen corn. Simmer for 10 minutes, stirring occasionally.
05 - In a large mixing bowl, whisk yellow cornmeal, all-purpose flour, granulated sugar, baking powder, and salt until evenly combined.
06 - In a separate bowl, whisk together whole milk, eggs, and melted butter. Incorporate wet mixture into dry ingredients, stirring until just combined. Fold in shredded cheddar cheese.
07 - Evenly distribute chili mixture into prepared baking dish. Sprinkle shredded Monterey Jack or cheddar cheese over chili.
08 - Gently spread cornbread batter over cheese and chili, smoothing the surface. Add sliced jalapeños if desired.
09 - Bake for 35-40 minutes, or until cornbread is golden and a toothpick inserted into the center comes out clean.
10 - Allow casserole to cool for 10 minutes before slicing and serving.