In a large bowl, combine the flour, sugar, baking powder, and salt. Once combined, add the cubed cold butter. With cold hands, rub the flour and butter together until it becomes crumbly. It should be able to hold its shape when squeezed. If you have a food processor, you can use it instead and it will make this process so much easier. Simply add the flour mixture and butter into the bowl of the food processor and let it go until just combined then return to the flour bowl. Be mindful, though, that the quickness of this method and the machine can generate heat which can melt the butter a bit, so don’t let it run for too long or let it process in pulses.
Create a well in the center of the flour mixture. Pour all of the milk into the well and whisk while slowly incorporating more of the flour. Fold to knead until the dough has no more powder but is still shaggy.
Turn the bowl out onto a floured surface. Shape the dough into a rough disk and roll to about 5cm or 2inch thickness.
Using a cookie cutter, knife, or any cutting tool you have, cut out scones of your desired size and shape. Transfer the scones onto a tray lined with parchment paper or a silicone mat.
For a glossy look, brush the tops of the scones with a beaten egg (alternatively you can use 1 egg yolk and about 4 teaspoons of milk).
Bake at 375°F/190°C for 15-20 minutes until golden brown on top. Let the scones cool for about 5-10 minutes before you handle them, and the plain scones are done! 完成です!