Preheat oven to 180 degrees C.
Sift the dry ingredients twice. Chop the walnuts roughly and mix in.
Combine oil, apple juice concentrate, yoghurt and vanilla and mix well. Add carrot and raisins. Mix again.
Beat egg whites until stiff. Gently fold them through the fairly stiff carrot mixture. Turn mixture into a foil lined, deep sided 20cm square tin. Cook for 1 hour. Cover with foil for 10 minutes. Remove foil lid and leave to cool.