Preheat the oven to 175 degrees Celsius.
Line a baking pan with parchment paper.
Make the flax egg (if using).
Shred the zucchini and squeeze out as much water as possible.
Mash the bananas in a bowl.
Add flax egg or regular egg, vanilla stevia drops to the mashed banana and combine.
Add oat flour, coconut flour, baking soda, cinnamon and nutmeg (if using) to the bowl and combine using a fork or spatula.
Fold in the shredded zucchini, chocolate chips and raisins (if using).
Add batter to the prepared baking pan and bake in the oven for 25-30 minutes.
Take out of the oven and let it rest for 5 minutes before cutting it.