In a bowl, combine flour, sugar, baking powder, salt, and cardamom powder.
Whisk the egg. Set aside.
Grate the frozen butter.
Add the grated butter to the flour mix. Using your hands, work the butter into the flour until it resembles coarse sand.
Mix in the cold cream and egg.
Halfway through mixing, add the golden raisins. Fold a few more times.
Dump the ruffly mixed dough into the tabletop. Using your hands, shape the dough into a round disk-like shape with a thickness of about 1½" (4cm) and a diameter of about 6"-7" (15-18cm). Work quickly to prevent melting the butter.
Make the cardamom sugar mix to sprinkle on top. Set aside.
Cut into 8 pieces. Brush each piece with milk or cream and sprinkle the cardamom sugar on top. Transfer to parchment paper and put it in the freezer for about 30 minutes.
Preheat the oven to 400F (200C).
After 30 minutes, transfer to a baking tray lined with parchment paper. Make sure you have about 2" (5cm) of space between each scone. They will expand as they bake.
Bake for about 18-25 minutes, depending on your oven. They should look light golden brown on top and around the edges.
Let them cool for a few minutes before enjoying.
Notes
Make sure the butter is very cold. I like to put it in the freezer for up to an hour before grating it.