Pre heat your oven to 220C / 425F / Gas mark 7. Prepare you baking sheet; I used baking parchment to line mine.
Sift the flour, salt and baking powder together in a medium sized bowl, add the butter and mix in until it resembles fine sand. You can use a food processor for this if you have one. I just used my hands.
Add the sugar and mix it in.
Add 2/3rds of the buttermilk and stir in with a fork, gently mix together, you don’t want to overwork this mixture otherwise it will make a tougher mixture and therefore a tougher scone.
Add the rest of the buttermilk and fold it in. Don't use it all if you feel your dough is sticking together sufficiently.
Transfer to a well-floured surface. For the plain scones you want to leave the mixture quite thick. If you are making blueberry scones you will want it to be a little thinner.
As you will be placing blueberries on one half of the scones and topping them with the other halves, in effect you are making a blueberry sandwich.
Once done pop them on your prepared baking tray.
Brush a little buttermilk on the tops of the scones and sprinkle with a little brown Demerara sugar. Caster or granulated white sugar will be fine if you have no Demerara to hand.
Bake in the oven for 15 to 20 minutes, until the tops are a olden brown colour and the bottoms sound hollow when tapped.
Pop them on a cooling rack to cool down.
I like these while they are still a little warm and they never last in my house long enough to fully cool down anyway :) but you can keep these in a tin for up to 3 days.