Preheat oven to 180C and line a loaf tin with greaseproof paper
Zest the orange and squeeze the juice
Grate the apples (with their skins on) and place in a saucepan along with around half of the orange juice and cook for 4-5 minutes until starting to soften. Remove from the heat
Chop the walnuts and dates and separate the eggs
Place the oil and sugar into a mixing bowl and whisk together until smooth. Add the egg yolks and whisk together. Add the cooked apple, grated butternut squash, orange zest, chopped walnuts and dates, spices, bicarbonate of soda and a pinch of salt. Mix well to combine. Add the flour and stir gently until fully combined.
Whisk the egg whites in a separate bowl until light and fluffy. Gently fold the egg whites into the mixture until incorporated without knocking out too much air.
Tip the mixture into the prepared loaf tin and level the top. Bake for 1 hour or until a skewer inserted in the centre of the loaf comes out clean. You may have to cover the loaf with foil half way through cooking to avoid the top becoming too brown.
Allow to cool completely before cutting into thick slices.