Preheat oven to 410F/210°C. Line a baking sheet with parchment paper or silicone mat.
In a large bowl, sift in cake flour, salt, and baking powder. Add granulated sugar and mix to combine.
Add cold butter to the flour mixture. Use a pastry cutter or bench scraper or your fingers to cut the butter into fine crumbs.
Make a well in the center of the mixture. Pour egg and cold milk. Use a spatula to combine the dough until well incorporated.
Scatter some flour onto the work surface and tip the dough out. Dredge the dough and your hands with a little more flour. Roll the dough with a rolling pin into 1-inch/2.5 cm thickness. Using a bench scraper, cut the dough into 2 even pieces. Stack one part over the other. Press slightly and roll the dough again. Roll and stack the dough 2-3 more times.
Roll the dough into 1-inch/2.5 cm thickness. Cut into 2.4-inch/6 cm rounds with a biscuit cutter. Make sure to press the cutter straight down and not twist your cutter.
Place the scones onto the prepared baking sheet. Brush the tops with milk.
Bake the scones for 15 minutes until risen and golden on top.
Eat warm or cold on the same day of baking, generously topped with jam and cream.
