Preheat oven to 385-degrees. Prepare mini muffin pan by applying nonstick spray in each well, though not all will be filled.
Whisk together all of the dry ingredients. Work the butter into mixture with a pastry blender or your fingertips until it resembles coarse crumbs; just as with making pie crust, you want those bits of butter in there.
Add the buttermilk and stir until just combined. Knead in the bowl until the dough just starts to come together and is still craggy and bumpy, adding more buttermilk if necessary. Don't over-knead or the bread will be tough and dense.
Use a tablespoon scoop or spoon to evenly dole out dough into the pan. Expect about eighteen mini muffins.
Bake for ten minutes. Use the toothpick test to check middle ones for doneness. Melt the remaining tablespoon of butter and brush it on the tops of the little rounds.
Leftovers freeze well, and are the perfect size to fit in lunches.