01 - Preheat oven to 400°F (200°C). Grease a 12-cup muffin tin or line with paper liners.
02 - Heat olive oil in a skillet over medium heat. Sauté onion for 2 minutes, then add garlic and ground beef. Cook until beef is browned, breaking up meat with a spoon.
03 - Stir in kidney beans, diced tomatoes, tomato paste, chili powder, cumin, smoked paprika, salt, and pepper. Simmer for 5–7 minutes until thickened. Remove from heat and allow to cool slightly.
04 - In a large bowl, whisk together cornmeal, flour, sugar, baking powder, baking soda, and salt.
05 - In a separate bowl, whisk eggs, buttermilk, and vegetable oil. Pour mixture into dry ingredients, stirring gently to combine. Fold in shredded cheddar cheese, if using.
06 - Spoon about 1 tablespoon of cornbread batter into the bottom of each muffin cup. Place 1 heaping teaspoon of chili filling in the center, then cover with more batter to fill each cup about three-quarters full.
07 - Bake for 18–20 minutes until muffins are golden and a toothpick inserted into the cornbread portion comes out clean.
08 - Allow muffins to cool in the tin for 5 minutes. Transfer to a wire rack and serve warm.