Butter a 900g loaf tin and line the base and ends with strips of baking parchment. Preheat the oven to 180°C, fan 160°C, gas 4.
Peel the bananas and put into a bowl, then mash them to a purée with a fork. Grate the apples into the bowl and mix.
Put the cinnamon and baking powder into a mixing bowl and sift both the flours on top, finally tipping in the bits of wholemeal that are left over in the sieve. Add the remaining ingredients, apart from the dried fruit and walnuts, and mix together thoroughly using an electric hand whisk. When the mixture is smooth, add the fruit and walnuts and stir through.
Pop the mixture into the prepared loaf tin, level and bake in the middle of the preheated oven for 1¼ -1½ hours, or until a skewer inserted into the loaf comes out clean. Allow to cool before slicing. Keep for up to a week in an airtight container.
Cook's tips: to add extra zing, try serving the Bramley apple and walnut loaf cake with a mixture of crème fraîche and lemon juice.
These ingredients make a good-sized loaf. If you want something smaller then halve the ingredients, use a smaller loaf tin, and cook for around 45-60 minutes. Or make the full loaf but freeze half for up to 1 month and simply defrost when you're ready to use it.