Preheat your oven to 375°F (190°C) and grease a mini muffin tin.
In a mixing bowl, combine the dry ingredients: cornmeal, flour, baking powder, baking soda, salt, and sugar.
In a separate bowl, whisk together buttermilk, egg, and melted butter.
Gradually fold the wet ingredients into the dry ingredients until just combined.
Stir in the diced jalapeño, shredded cheddar cheese, and corn kernels.