Preheat the oven to 350 F, and grease and line a loaf pan with parchment paper.

In a medium bowl, mix the flour, milled flaxseed, baking soda and salt together with a whisk. Set it aside.

Add the bananas and prunes to a food processor and blitz until the prunes are quite broken down. Add the butter, white sugar and brown sugar and pulse until they are well combined.

Add in the lemon, milk, and eggs and pulse the machine until they are all incorporated. (You could add all the wet ingredients + sugar to a blender if you don't have a food processor. Perhaps add the prunes slowly so they don't get jammed in the blade of the blender.)

Pour the wet ingredients from the food processor into the bowl of the dry ingredients. Mix with a wooden spoon or a spatula until they are just combined and then mix in the raisins.

Pour the batter into the prepared loaf pan and bake at 350 F for 50-55 minutes or until a toothpick comes out clean when tested.