Preheat your oven to 400°F (200°C). Lightly grease a 9x13 inch baking dish or a 10 inch cast iron skillet if you want a rustic look.

In a large skillet over medium-high heat, warm the olive oil. Add the ground beef and cook, breaking it up with a spoon, until browned, about 5 to 7 minutes. Drain any excess fat if needed.

Add the diced onion and bell pepper, and cook for 3 to 4 minutes until softened. Stir in the minced garlic and cook for 30 seconds until fragrant.

Add the chili powder, cumin, smoked paprika, salt, and pepper. Stir well to coat the meat and vegetables. Then add the black beans, diced tomatoes (with their juices), and frozen corn. Bring to a simmer and cook for 5 minutes, letting the flavors meld. The mixture will thicken slightly. Remove from heat.

Transfer the meat mixture to the prepared baking dish. Sprinkle the shredded cheese evenly over the top.

In a separate bowl, whisk together the cornmeal, flour, sugar, baking powder, and salt. In another bowl, beat the egg, then whisk in the buttermilk and melted butter. Pour the wet ingredients into the dry ingredients and stir just until combined. Do not overmix. The batter will be thick and slightly lumpy.

Drop spoonfuls of the cornmeal batter over the cheese layer. Use a spatula to gently spread it into an even layer, but it doesn't need to be perfect. The batter will puff as it bakes.

Place the dish in the preheated oven and bake for 20 to 25 minutes, or until the topping is golden brown and a toothpick inserted into the center comes out clean.

Let it rest for 5 to 10 minutes before serving. This allows the casserole to set and makes slicing easier.

Spoon portions onto plates and top with fresh cilantro, a dollop of sour cream, or a drizzle of salsa.