Preheat the oven to 170 degrees Celsius (340 degrees Fahrenheit).
In a large bowl, add the brown sugar and butter, and use a hand mixer to cream them together.
Add the eggs one by one, beating well after every addition.
Sift in the flour and baking powder, and use a spatula to bring everything together.
Add the dried fruit and mixed spice, and mix well to have all the ingredients incorporated.
Line a 12-hole muffin tin with paper cases, and divide the mixture evenly.
Bake for 25-30 minutes or until the top is firm and a skewer inserted in the middle comes out clean.
Remove the cakes from the oven and leave them to cool completely.
To make the icing, sift the icing sugar, and add the orange juice to it.
Mix well to get a smooth, lump-free paste.
Use a teaspoon of the mixture to top each cake, it looks even better if the icing runs a bit down the sides.
You can also decorate them with any sprinkles, Christmas edible figures or anything else that takes your fancy.