Preheat oven to 220 degrees C. Grease a baking tray.
Sift the dry ingredients into a bowl and rub in the butter until the mixture resembles coarse crumbs.
Gradually add the buttermilk, stirring with a fork to make a firm dough. Roll the dough out to about 1/2cm thick. Cut out rounds with a 5cm biscuit cutter and place on baking tray. Bake 12-15 minutes or until golden. When cool, draw a cross on the top of each like a hot cross bun.