Preheat the oven to 400. Put the first tablespoon of butter in a 9 inch or 8 inch pan and put the pan in the oven while it preheats so that the butter will melt. Set the timer for 5 minutes so you won't forget about it!
In a large bowl, mix all the dry ingredients. Make a well in the center.
To the well, add the buttermilk, melted butter, and egg. If using the bacon, add it too. Stir those things together, then stir all together (gently) to make a smooth and thick batter.
Scrape into the buttery pan and bake at 400 for about 25 to 30 minutes. A 9 inch square pan should take 25 minutes, but an 8 inch pan will take about 32.
Let cool for about 15 to 20 minute before serving.