Preheat oven to 400°F; brown beef in a large oven-safe skillet or pot over medium-high, breaking it up.
Cook onion and pepper with beef 5 minutes until softened; drain excess fat.
Stir in beans, tomatoes, chili powder, cumin, garlic powder, salt, and pepper; simmer 10 minutes to meld flavors.
Sprinkle cheddar evenly over chili; transfer to a greased 9x13-inch dish if skillet is not oven-safe.
Prepare cornbread batter according to package; pour evenly over chili and cheese.
Bake 20-25 minutes until cornbread is golden brown and a toothpick inserted in center comes out clean; cool 5 minutes before serving.