In a bowl mix apples with sugar; cover and set to one side. In another bowl drizzle sultanas with rum and cover; set to one side and steep overnight.
The next day preheat oven to 200 C / Gas 6. Grease two loaf tins or line with greaseproof paper.
Mix apples, sultanas and rum together in a bowl. Mix all the remaining ingredients in a separate large bowl. Add the apple mixture and stir till evenly combined and moistened with no traces of flour remaining.
Spoon mixture into prepared baking tins; bake in preheated oven till browned and firm about 1 hour. Let cool completely before cutting.