Brown the ground beef in a skillet over medium heat with the diced onion and minced garlic until the meat is no longer pink. Drain excess fat.
Transfer the beef mixture to the slow cooker. Add the chopped chipotle peppers, diced tomatoes, kidney beans, beef broth, smoked paprika, cumin, and salt and pepper. Stir to combine.
Cover and cook on low for 6 to 8 hours until the chili thickens.
About 30 minutes before serving, preheat the oven to 400°F. In a mixing bowl, stir together the cornmeal, flour, and baking powder. Add the milk, egg, and melted butter, then fold in the shredded cheddar cheese.
Pour the cornbread batter into a greased baking pan and bake for 20 minutes until golden on top.
Ladle the chili into bowls and serve with pieces of warm cornbread on the side.