Preheat your oven to 400°F. Place two tablespoons of butter in the cast-iron skillet and place the skillet in the oven for about five minutes while you mix the cornbread batter.
To a medium mixing bowl, add the cornmeal, flour, baking powder, baking soda, and salt. Use a whisk to mix the dry ingredients together.
To a small mixing bowl, add the buttermilk, honey (if using), and eggs. Use a whisk to beat the wet ingredients together until combined.
Make a well in the center of the cornmeal mixture and pour the buttermilk mixture into the well. Use a rubber spatula to mix the batter until no more dry cornmeal is visible. Pour the melted butter into the batter and mix with the rubber spatula until combined. Remove the skillet from the oven and carefully pour the batter into the hot skillet.
Smooth the cornbread batter out into an even layer and bake the cornbread in the preheated oven for 20-25 minutes or until golden brown on top. Allow the cornbread to cool for 10 minutes, slice, and enjoy! Serve cornbread slices with butter slathered on them if desired.
Measure your cornmeal and flour properly by weighing them with a kitchen scale or using the spoon and level method.
Leftover buttermilk cornbread can be wrapped in plastic wrap or foil and stored at room temperature for up to three days and in the refrigerator for up to a week.