Preheat oven to 425°F (220c)
In a large bowl mix together the flour, salt and baking powder. Add the cubed butter and rub the mixture together with your fingers until the mix becomes crumbly. Then add the sugar (and currant or raisins if you are adding them) and mix together.
Microwave the milk for about 30 seconds until it is warm. Add the vanilla extract to the warm milk and mix.
Put an empty baking sheet into the oven.
Make a well in the dry scone mix, then add the milk mixture and quickly mix it together.
Put the dough onto a floured surface. With floured hands fold the dough 2-3 times until the dough is smoother. Flatten the dough down to a round shape, approximately 1 inch thick.
Flour a 2 inch round cutter, or the rim of a glass, and cut out circles until you run out of space in the dough. Re-flatten the remaining dough into another round and continue cutting out circles. Repeat until the dough is gone. Place the cut out rounds onto a piece of parchment paper. Bush the tops of the dough with the beaten egg.
Take the hot baking sheet out of the oven. Carefully place the parchment paper with the cut out scones on the hot baking sheet. Put the baking sheet back in the over and bake scones for 10 minutes, or until the scones are golden.
Serve warm, or cold topped with clotted cream and jam.