- Set the oven to 200 C / fan oven 180 C / Gas Mark 6
- Grease a large baking sheet.
- Sieve the flour, baking powder and mixed spice into a bowl.
- Add the butter and rub into the flour until the mixture resembles breadcrumbs.
- Add the sugar and the fruit, stir and then add the egg and milk and mix to form a dough.
- Spoon rough, golf ball-sized mounds of the mixture onto the baking tray. The mixture should make approximately 16 cakes.
- Sprinkle each mound with a little Demerara sugar.
- Bake in the oven for roughly 10 minutes, until light brown. Check after 7 minutes and rotate the baking tray if necessary to give an even colour to all the cakes.
- Allow to cool on the baking tray for 5 minutes before transferring to a cooling rack.
- Rock cakes are best eaten on day of baking.