Preheat oven to 425°F (220°C). Sift together all-purpose flour, baking powder, baking soda, sugar, and salt into a large bowl.
Add cold butter and cut it in with a dough blender until it resembles coarse breadcrumbs.
Pour in 1 cup/240ml buttermilk and mix with a spatula until a sticky dough forms.
Turn dough onto a lightly floured surface and pat it out to ¾ inch thickness. Cut dough with 2-inch fluted round cutter and place cut out dough on a cookie sheet.
Gather the scraps together, reshape, pat it out to ¾ inch thickness, and cut with 2-inch fluted round cutter until all dough is used up. You should get 10 to 12 scones.
Brush the tops with remaining 2 tablespoons of buttermilk.
Bake in preheated oven for 20 minutes or until golden brown.