Brown chopped bacon in a 10-inch cast iron skillet. Add the garlic and jalapeno and saute until softened.
In a bowl, combine the cornmeal, baking powder, baking soda, salt, and pepper and mix well. In a small bowl, combine the buttermilk, eggs, and melted butter. Add to dry ingredients and stir just to combine. Quickly pour the cornmeal batter into the skillet.
Bake for 25 to 30 minutes, or until firm and golden brown on top. Let sit for 5 minutes, then turn out onto a cutting board. Cut into wedges and serve hot with butter on the side.