Preheat oven to 390F (200C)

Mix the flour, baking powder, baking soda, salt and orange zest in a large bowl. Rub the butter by hand into the flour using your fingertips until the mixture resembles fine breadcrumbs. Stir in the sugar and add the frozen cranberries.

In another bowl, mix the milk with apple cider vinegar and the vanilla extract.

Gradually add the milk mixture to the dry ingredients until you have a soft dough. It is far better that the scone mixture is on the wet side, sticking to your fingers, as the scones will rise better. Don't overwork the dough.

Turn the dough onto a lightly floured surface and flatten it out with your hand. Press into a neat disc (about 2cm high) and cut into 6 equal wedges.

Optional: Brush the tops of the scones with the egg wash (whisk together 1 egg and 1 tablespoon of milk) and sprinkle some granulated sugar.

Bake for 15 to 20 minutes or until lightly golden and cooked through.