Measure the sultanas, raisins, apricots and apple into a bowl with the orange juice. Add the measured brandy (rum or sherry), stir and leave to marinate for about one hour.
Put the measured butter, sugar and grated orange rind into a large bowl and cream together with a wooden spoon or a hand-held whisk until light and fluffy. Gradually beat in the eggs, adding a little of the measured flour if the mixture starts to curdle.
Sift together the flour and mixed spice, then fold into the creamed mixture with the breadcrumbs and the nuts. Add the soaked dried fruits with their soaking liquid and stir well.
Generously butter a 1.4 litre/2½ pint pudding basin. Cut a small disc of foil or baking parchment and press into the base of the basin.
Spoon into the prepared pudding basin and press the mixture down with the back of a spoon. Cover the pudding with a layer of baking parchment paper and foil, both pleated across the middle to allow for expansion. Tie securely with string and trim off excess paper and foil with scissors.
To steam, put the pudding in the top of a steamer filled with simmering water, cover with a lid and steam for eight hours, topping up the water as necessary.
To boil the pudding, put a metal jam jar lid, or metal pan lid, into the base of a large pan to act as a trivet. Place a long, doubled strip of foil in the pan, between the trivet and the pudding basin, ensuring the ends of the strip reach up and hang over the edges of the pan. This will help you to lift the heavy pudding basin out of the pan of hot water when it has finished cooking.
Lower the pudding onto the trivet and pour in enough boiling water to come half way up the side of the bowl. Cover with a lid, bring the water back to the boil, then simmer for about seven hours, until the pudding is a glorious deep brown colour, topping up the water as necessary.
For the brandy butter, place the butter into a mixing bowl and cream with a wooden spoon until light and fluffy – or for speed use an electric hand-held mixer. Beat in the sieved icing sugar until smooth, then add brandy, rum or cognac, to taste. Spoon into a serving dish, cover and set aside in the fridge.