Preheat oven to 400 degrees. Grease a 12 cup muffin pan and set aside.
In a large bowl, whisk together the dry ingredients - cornmeal, flour, sugar, baking powder, baking soda, and salt, removing any clumps.
Add the buttermilk, melted butter, and eggs to the dry ingredients until just combined (as soon as you don't see any streaks of dry ingredients anymore).
Portion batter into prepared muffin pan. Bake for 11-13 minutes, or until toothpick inserted into center comes out clean or with a few crumbs. Edges should be browned and tops should have a light brown color.
Allow to cool for up to ten minutes before removing muffins from the pan. As they cool, they will contract from the sides of the pan, making them easier to remove. If needed, use a butter knife to gently pop your muffins out of the pan.
Optionally, brush the tops with melted butter before serving.
Muffins are best served same day, and leftovers enjoyed within two days of preparing.
Leftover muffins can be frozen and thawed for future meals. Once muffins are cooled to room temperature, wrap in wax paper or foil, then store in a freezer-safe bag or tightly sealing container. Bread will keep for 3 to 6 months when stored properly.
Buttermilk substitute - in a liquid measuring cup, add 1 tablespoon of lemon juice or white vinegar. Fill with milk (to the 1 cup line), then allow to set for 5 minutes. This will curdle your milk, creating a buttermilk substitute.