Preheat the oven to 220°C.
Line a baking tray with baking paper and grease lightly with butter.
Rub 450g of flour and the butter together in a bowl until breadcrumbs form.
Mix in the sugar, two eggs, and baking powder using a wooden spoon.
Gradually add milk while stirring to form a soft, wet dough.
Turn the dough onto a floured surface and sprinkle with the remaining flour.
Fold and turn the dough several times until smooth, without overworking.
Roll the dough out to 2.5cm thickness.
Cut out rounds using a floured pastry cutter and place on the tray.
Re-roll leftover dough scraps to cut more rounds.
Rest for a few minutes, then glaze tops with beaten egg and salt.
Bake for 15 minutes until risen and golden brown.
Cool and serve with jam and clotted cream.