Preheat the oven to 180°C (356°F).
In a bowl, mix cake flour, baking powder, and salt.
Add cold butter and mix with your hands until the mixture resembles coarse crumbs.
Separately mix milk, sugar, and egg, then add to the dough and combine.
When the dough comes together, form it into a ball and roll out to 2cm thick.
Shape into rounds and place on a baking pan.
Bake in the preheated oven for 15 minutes.
Once the scones have cooled, cut them in half and spread with jam.