Preheat oven to 375 degrees. Line two baking sheets with parchment paper and set aside.
Combine flour, baking powder, baking soda, salt and sugar in a large mixing bowl.
Cut the butter into the flour until the mixture resembles coarse crumbs using a pastry blender or two knives (I used a food processor).
Add the buttermilk and stir with a wooden spoon until the dough just comes together.
Turn out onto a floured surface and pat into a rectangle about 1 inch thick.
Cut dough into 12 squares (I like this shape because it eliminates all scraps). Place on baking sheets and bake for 18-20 minutes or until golden brown