1. Preheat oven to 220C (200C fan-forced). Line a baking tray with baking paper and set aside.
2. Sift the flour,icing sugar,baking powder and salt into a large bowl. Make a well in the centre,add the cold butter to the well,and lightly rub the butter into the flour between your thumbs and fingertips until it is no longer bitsy,lifting the mixture above the bowl to get air into it.
3. In a small bowl or jug,whisk the egg into the buttermilk,and set aside 2 tbsp for glazing. Pour the remaining mixture into the flour,mixing lightly with a spatula until a soft,slightly sticky dough just comes together. Turn onto a floured bench. Flour your hands and form the dough into a rough ball,then gently press out to a 2-3cm layer.
4. Flour the inside of a 6cm-wide pastry cutter,and cut out as many scones as you can,arranging them quite close together on the lined tray. Bring the offcuts together,press out again and cut out remaining scones – you should get about 12 in total.
5. Brush the tops with the reserved buttermilk mixture and bake for 10-12 minutes until puffed,golden and firm when pressed in the middle.
6. Remove from oven and wrap in a clean tea towel to keep warm. Serve with butter or jam and cream.
Tip: You know you're rubbing the butter into the flour properly when the floury mess stops at the first knuckles of your hand.