Preheat oven to 425°F (220°C). Line a large baking sheet with parchment paper or a silicone baking mat and set aside.
Sift the flour, baking powder and salt through a sieve into a large mixing bowl.
Add the cold cubed butter to the mixing bowl. Using a pastry cutter, incorporate the butter into the flour until it is in small crumbs.
Whisk the sugar, milk, and egg in a separate bowl. Pour into the dry ingredients and mix gently, just until a soft dough forms. Do not over mix.
Press or roll out the dough into a circle on a lightly floured cutting board. The dough should be about 2 cm thick.
Using a round cookie cutter, cut out 8 scones, being careful not to twist the cutter. Place the scones on the baking sheet.
You can now opt to place the scones in the freezer for 20-30 minutes to make them extra cold. This will help with the rising. Just don't leave them longer than 30 minutes.
Brush the tops of the scones with milk.
Bake for 12-15 mins until golden brown.