Preheat the oven to 200C or Gas Mark 6.
Prepare a baking tray by sprinkling flour on it, then set it aside.
Place the flour, baking powder and salt into a mixing bowl.
Cut the butter into cubes and place it in the bowl.
Rub the butter into the dough until it resembles breadcrumbs.
Add your additional ingredients and mix them in.
Add one large egg to the mixture and mix with a fork.
Add the buttermilk a little at a time until there is no flour in the bowl.
Turn the bowl out onto a clean surface and lightly shape it into a rectangle about 2.5 centimetres deep.
Use a 60mm cookie cutter to cut out the shapes.
Lift the shapes and gently place them on the baking tray.
Whisk the remaining egg for an egg wash and brush it on the top of each scone.
Bake for 12 minutes or until the scones are fully risen, golden and fluffy.
