Combine cornmeal and buttermilk in a bowl, set aside for 15-30 minutes (see note).
Heat oven to 375 degrees F. Place 12 inch cast iron skillet or 8x8 baking dish in the oven to preheat.
Whisk flour, baking powder, baking soda, and salt together, set aside.
In a large bowl, combine soaked cornmeal, 3 tablespoons of the melted butter, yogurt, honey, and eggs. Mix well.
Fold in dry ingredients, mix until just combined.
Add the remaining 2 tablespoons of butter to the preheated skillet or 8x8 baking dish, making sure it is covering the bottom of the skillet or 8x8 baking dish.
Pour batter into the skillet or baking dish, and place back into the oven.
Bake for 20 minutes or until a toothpick comes out with a few crumbs on it.
Greek or plain yogurt can be used, I find the flavor of greek yogurt is sometimes too strong for this recipe. Sour cream can be substituted in place of yogurt. I have tested a few different soak times for the cornbread and 15 minutes is the minimum amount of time but you, of course, soak it longer, up to 30 minutes.