Combine the sultanas, cranberries and prunes with the brandy and orange juice, stir and soak for 4 hours.
Preheat the oven to 375F /190 C/ gas mark 5. Grease a 23 cm square baking pan and line with parchment paper. Set aside.
In a bowl combine the flour, baking powder, mixed spice and salt and stir using a whisk. Set aside.
In another bowl beat together the eggs, sugar and oil for about 2 minutes until fluffy. Add the nuts, fruit mixture and orange zest and stir. Add the flour mixture and stir just to combine (do not overstir).
Pour the mixture into the prepared pan, smooth out the top and bake in the centre of the oven for 30 minutes. Remove from the oven and leave to cool in the pan for 10 minutes. Lift the cake out with the paper and place on a cooling rack to cool completely.
Make the icing by combining the icing (powdered) sugar with 1 tablespoon of either orange or lemon juice and stirring until smooth. Drizzle the icing over the cake, scatter some lemon/orange zest and serve!
Substitutions: I used sultanas, cranberries and prunes, but you can use a different combination of dried fruits as well as adjust the proportions to suit your preference. I used a combination of walnuts and brasil nuts but pecans, almonds or macadamia nuts would work well too. If you prefer to make this fruit cake alcohol free simply add a little more orange juice into the fruit mixture.
Soaking the fruit: Try to soak the fruit for at about 4 hours or leave to soak overnight.
Batter: Do not overstir the batter. Once you've combined all the ingredients stir only until the flour is no longer visible.
Spice: I used mixed spice but pumpkin spice would be a good alternative.
Storing: Store in a plastic container for up to 3 days.
Preparation time does not include the time needed to soak the fruit.