Pour the flour, salt, sugar and yeast into a planetary mixer with the leaf and mix the ingredients at speed 1 (in the absence of a planetary mixer mix everything in a bowl).
Add the butter at room temperature and the milk and mix for a few minutes until the dough is compact and sticky. Wrap the dough with the film and let it rest in the pre-cooled blast chiller with the function of blast chilling for 15-20 minutes. After this time, roll out the dough, with the help of a rolling pin, in a sheet about 1.5 cm high. With the help of a 6 cm diameter pastry ring, make discs and place them on a plate covered with oven paper.
Beat the egg with half a glass of milk and brush the surface of the scones, then bake in the preheated oven to 180ºC ventilated for 15 minutes. Take out the scones and cool them in the pre-cooled blast chiller with the function of blast chilling for about fifteen minutes. Then cut them in half and fill them with a little crème fraiche and a little jam.