Preheat your oven to 180 C/350 F/Gas Mark 4
Sift the flour into a bowl
Add the salt and baking powder
Cut the butter into cubes and use your fingertips to rub in the butter until the mixture resembles coarse breadcrumbs
Beat the egg in a cup or bowl. Keep a little of the beaten egg to glaze the scones.
Make a well in the centre of the flour/butter mix and add the beaten egg and 3 tbsp of buttermillk
Combine the wet and dry ingredients gently using a knife. If the mix is too dry then add more buttermilk and continue to combine
Add the frozen raspberries and mix gently
When the dough has just come together, remove it from the bowl and knead it gently on a floured board
Roll the dough out to about 2cm thick and use a scone or cookie cutter to shape your scones. Be care not to twist the cutter as you cut
Glaze the scones with the remaining beaten egg. If you forgot to keep back some egg, then use some milk instead
Bake the scones in the oven for about 15 minutes.