Preheat the oven to 190°C/375°F/gas mark 5. Chop the dried apricots finely and put them into a bowl, then stir in the grated orange rind and ground cinnamon. Put the orange juice into a fairly shallow ovenproof earthenware dish that is big enough to hold the apples. Make a shallow cut round the middle of each apple and remove the cores. Fill each apple with the chopped apricots and place in the dish. Crate the nutmeg over the apples and pour the rum and lemon juice around them. Finally, sprinkle the apples with the muscovado sugar, top each one with a good knob of the butter and bake on the centre shelf of the oven for 1-1¼ hours. Then drain the juices into a saucepan and boil fiercely until they become thick and syrupy. Pour the juices over the apples and serve immediately.