Preheat oven to 350F and line a baking sheet with parchment paper.
In a large bowl, combine all dry ingredients and stir together. Add buttermilk and mix with a large spoon (or with your hands, shaping your fingers into a “claw”) until the dough comes together. You might need two tablespoons more or less buttermilk depending on the weather. The dough should be moist, but not so sticky it is very hard to handle.
Shape into a round and place on baking sheet. Cut an X into the top with a sharp knife and bake for about 45 minutes, until dark golden. A toothpick will come out clean.
Cool on a wire rack for about 10 minutes before slicing.