Briefly knead flour, baking powder, sugar and butter. Gradually knead in 125-150 ml milk and work into a smooth dough. Roll out dough on a floured work surface to a thickness of 1-2 cm.
Cut out 20 circles (5 cm Ø). Place on a baking tray lined with baking paper. Whisk the egg yolk and 2-3 tablespoons of milk. Spread scones with it. Bake in a preheated oven (electric cooker: 200° C/ convection oven: 175 °C/ gas: level 3 ) for 10-12 minutes.
Serve scones with jam and double cream or butter.