I have only baked the cake using the pulp from my juicing machine, but I think the cake can still be made without the machine. If you do not have a juicer machine, mash some banana. For the orange, peel and remove as much of the white pith as possible, segment, place in blender and pulse for a couple of seconds just enough to break it up, drain off the juice and use the pulp for the cake.
Whether you use the juicing machine pulp or the other method it is important to remove as much of the white pith as possible, this will prevent bitterness in the cake.
Whole grain oat flour can be purchase at your local health food store, BIo shops, or
online. Almond meal can also be
purchased at those places or made at home. Simply place some unblanched almonds into a coffee grinder or food processor and pulse until it becomes a fine meal.