Turn your oven on to 220 degrees/200 degree fan/ gas mark 6 and place a large baking tray inside to heat upPlace the dry ingredients into a food processor and blend until well mixed. Alternatively place in a large bowl and mix well by handAdd the butter into the dry ingredients and either blend until the mixture looks like fine breadcrumbs, or rub the butter into the flour by handAdd the yoghurt and milk and combine into a dough that just holds togetherFlour a clean dry work surface and empty the dough onto itKnead until you have a rough ball then press out with your hand until around 2cm thickUsing a floured straight edged circular 7cm diameter cutter, cut out your scones. You should get four before bringing the dough back together to make another, then repeating with the final piece of doughRub the tops of the scones with milk and sprinkle with a little sugar if you desireCarefully remove the hot baking tray from the oven and quickly place the scones onto itBake the scones for around 15 minutes until golden on topAllow to cool for around 5 minutes (or fully) before cuttingEat on the day of baking or freeze and re-heat in the microwave