Preheat your oven to 400°F. In a large oven-safe skillet or pot, brown the ground beef over medium-high heat, breaking it up as it cooks.
Add diced onion and bell pepper to the beef and cook for 5 minutes until softened. Drain any excess fat.
Stir in kidney beans, crushed tomatoes, chili powder, cumin, garlic powder, salt, and pepper. Let it simmer for 10 minutes to let the flavors meld together.
Sprinkle cheddar cheese evenly over the chili. If your skillet isn't oven-safe, transfer the chili to a greased 9x13-inch baking dish.
Prepare cornbread batter according to package directions. Pour the batter evenly over the chili and cheese layer.
Bake for 20-25 minutes until the cornbread is golden brown and a toothpick inserted in the center comes out clean. Let it cool for 5 minutes before serving.