Preheat oven to 200c.
Combine buttermilk and cream in a jug and set aside.
150 ml buttermilk, 150 ml thickened cream
In a large bowl, combine self-raising flour, caster sugar and cinnamon then whisk to combine.
340 g self-raising flour (self-rising flour), 3 tablespoons caster sugar, 1 teaspoon cinnamon
Add the cream mixture (reserve a dribble in the jug for brushing - see my notes) to the bowl with the dry ingredients along with the vanilla.
Combine using a flat-bladed knife, using your hands to bring it all together for the final strokes (the dough should still look shaggy).
Turn the dough out onto a lightly floured surface and knead very lightly until it just comes together - it doesn't need to be totally smooth - you want to knead it as little as possible.
Pat the dough into a flat disc approximately 20cm (8") in diameter and place on a floured baking tray, cut into 8 equal wedges using a floured knife or bench scraper.
Brush the top of the dough with the leftover cream mixture, then sprinkle with demerara sugar.
1-2 teaspoon demerara sugar
Separate the portions slightly, then bake for 13 - 15 minutes or until the scones sound hollow when you tap them.