Start off by creaming together the butter and caster sugar.
Next, beat together the eggs and milk, and add to the butter and caster sugar. Whisk well.
Sift in the baking powder and flour, and then fold everything together.
Grate the zest of the blood orange, and fold into the mixture. Pour the mixture into a loaf tin.
Bake in a preheated 180 C / Gas 4 oven for roughly 40 minutes, depending on your oven. Insert a skewer into the centre; if it comes out clean, your cake is done.
Once the cake is out of the oven, set it aside on a cooling rack and make the drizzle. The drizzle needs to be put on the cake whilst it is still warm to allow it to seep into the cake.
Combine the granulated sugar with the juice of the blood orange. Use a fork to make holes into the cake and then pour the drizzle over top. It will soak into the cake, carrying the flavour with it. Enjoy!
If you don't want to use a blood orange, or can't find one, the cake can also be make with a regular orange, or a lemon to get a classic lemon drizzle cake.