Coconut flour has a different texture to all-purpose flour – it is more absorbent (which means it absorbs more of the wet ingredients), which is why you need a smaller quantity of coconut flour compared with regular flours.  Coconut flour also has no gluten (protein which gives structure to baked goods) – therefore we add eggs (including whipped egg whites) to help give the batter structure and help make these lighter and fluffier.