Combine oil, golden syrup and rum in a heavy-based saucepan. Cook over medium low heat for 3-4 minutes or until mixture just comes to a boil. Remove from the heat and add sugar. Stir until sugar dissolves. Add mixed fruits and leave aside to cool for about an hour.
Preheat oven to 170°C. Grease, line and grease the base and sides of two 16.5 x 6.5cm loaf pans with baking paper.
Pour the cooked fruit mixture into a mixing bowl and add in the eggs, one at a time beating well after each addition.
Sift in self-raising flour and mixed spice over the fruit mixture. Stir gently with a wooden spoon. Add the nuts leaving a little to be sprinkled over as a topping.
Transfer mixture into prepared pans and smooth the surface. Sprinkle over with some remaining nuts.
Bake for 45-50 minutes or until cooked through when tested with a skewer. Allow to cool completely before removing out from the pans.