Preheat the oven to 230 degrees C. Move the oven rack so it's positioned near the top of the oven for baking.
Sift the flour, salt, baking soda, cream of tartar, cinnamon and mixed spice into a large bowl. Rub in butter until the mixture resembles bread crumbs.
In a small saucepan, gently heat the milk and stir in the sugar and treacle until dissolved. Remove from the heat and pour into the dry ingredients. Stir until it turns into a soft dough.
Turn the dough out onto a floured surface and knead lightly until smooth.
Use a rolling pin to roll out to 2 -3 cm thickness. Stamp out scones with scone cutter or a glass, rerolling dough until it has all been used. Place the scones on a lightly greased or floured baking tray.
Bake for 12 to 15 minutes in the preheated oven, until the bottoms are lightly browned.