Preheat oven to 220ºC (200ºC fan-forced). In a bowl, sift flour, baking powder, sugar and salt.
Add butter and use your fingers to rub it into the flour mixture until all of the lumps have disappeared.
Make a well in the middle and add buttermilk and blueberries.
Using a knife, 'slice' the wet ingredients in to the dry to combine. This method will prevent the blueberries from bleeding too much in to your dough and ensures you don't overmix.
Once dough has just come together, turn out on to a floured surface. Gently squash the dough together.
Roll out into a flat disk approximately three centimeters in height. Using a 6.5 centimetre cookie cutter, cut out scones. Place on a baking tray - scones do not need to touch. Brush tops with remaining buttermilk.
Bake for 15-17 minutes until the tops begin to go golden brown. Remove from the oven and allow to cool slightly. Serve with butter or whipped cream and blueberry jam.