Preheat the oven to 200°C/180°C fan/400°F/gas mark 6. Line a baking sheet with baking parchment.
Place the milk and treacle in a jug, microwave for a few seconds, just until it is warm enough to stir the treacle into the milk, don't let it get hot. (You can also do this in a pan on the stove). Pop the mixture in the fridge until cool.
Mix the flour, baking powder, mixed spice, cinnamon and a pinch of salt together in a large bowl.
Add the cold butter and rub it in using your fingertips until the mixture resembles fine breadcrumbs and no lumps of fat remain.
Stir in the sugar.
Pour in the cooled treacle mixture and stir to form a soft, sticky dough. If it is too dry add a drop more milk. Mix it just enough to form a smooth dough, do not knead it.
Pat the dough out on a floured surface to about 4cm / 1 ½ inches thick.
Use a floured 6cm round cutter to cut out as many scones as you can. Bring together the scraps, pat out the dough again and cut out more scones.
Place the scones on the lined baking tray and gently brush ONLY the tops with milk.
Bake for 15-20 minutes until well risen, browned and firm to the touch. They should sound hollow when tapped on the bottom.
Transfer the baked scones to a wire cooling rack to cool slightly before serving. Best eaten on the day they are baked.