Add the orange zest and granulated sugar in a large mixing bowl. Use your fingers to rub the zest into the sugar to release the orange oils. Add the flour, baking powder, cardamom, and salt, and whisk it together.

Chop the cold butter into cubes. Add it to the dry ingredients and use a pastry cutter to cut the butter into pea-sized crumbs, ensuring the pieces stay cold and do not melt into the flour.

In a small bowl, use a fork to whisk the buttermilk, vanilla, and egg gently. Make a well in the middle of the dry ingredients and pour in the cream mixture. Stir until just combined. The mixture will be slightly sticky and maybe a little crumbly. It should hold together. If it is too dry, add a splash more cream. Don’t overwork the dough at this point.

Tip the mixture onto a lightly floured surface. Press it into a ball and flatten it into an 8-inch/20cm disc. Cut the dough into 8 equal-sized pieces. Place the pieces onto a plate and refrigerate them while the oven is preheated.

Preheat the oven to 400°F (200°C). Line a baking tray with parchment paper. Brush the tops of each scone with buttermilk and an optional sprinkle of granulated sugar.

Bake the scones for 20-25 minutes, until puffed and golden brown. Remove them from the oven and let them cool for 10 minutes before glazing

Orange glaze
In a bowl, whisk together the confectioner's sugar and orange juice. If the glaze is too thin, add a bit more confectioners sugar. If it is too thick, add more orange juice or a splash of milk or water to thin it out.

Drizzle the glaze over the scones.