In a large bowl, whisk together the gluten free flour blend, sugar, baking powder, xanthan gum and salt.

Add the cold cubed butter and work it into the dry ingredients until you get a mixture resembling breadcrumbs, with a few pea-sized pieces here and there.

Add the cold buttermilk and vanilla, and stir everything together until the dough starts clumping together in places but it’s still uneven with some patches of dry flour.

Add the blueberries (if you’re using frozen ones, don’t thaw them!) and stir well until they’re evenly distributed and most of the flour has been hydrated.

Turn out the dough onto a lightly floured surface and use your hands to press it together into a rough ball.

Press the dough into a roughly 7-inch (18cm) disc, about 1 inch (2.5 cm) thick.

Cut it into 8 wedges, either with a sharp knife or with a straight-edged metal pastry cutter.

Transfer the scones onto a lined baking sheet, cover with a sheet of plastic wrap/cling film and chill for at least 15-20 minutes.

Pre-heat the oven to 400ºF (200ºC) and line a large baking sheet with parchment/baking paper.

Place the chilled scones onto the lined baking sheet, spaced apart as far as possible.

Brush them with a bit of extra buttermilk and sprinkle with granulated sugar.

Bake them at 400ºF (200ºC) for 20-22 minutes until golden brown on top and slightly darker around the edges.

Once baked, cool them on the baking sheet for about 5 minutes, then transfer them to a wire cool.