For the donuts, mash the bananas, add the egg whites and stir well. Add the protein powder, coconut flour, cacao powder and stir well until all the lumps are removed.
Shred the zucchini into the batter and mix well. Stir well and let sit 2 minutes before adding milk of choice.
Stir in milk (starrting with 2 tbs) cacao nibs, baking powder and baking soda. Mix well.
Create 12 donut holes by tearing off strips of parchament paper and rolling them into balls.
Spray muffin tin well with non-stick spray and add the parchament paper balls to the center.
Spoon in the donnut mixture and bake at 350F for 20 minutes.
Take the donuts out of the oven and allow to cool slightly.
Remove the donuts with a knife and place on a cooling rack. Transfer to fridge and allow to cool completely.
Once donuts are cooled, make the chocolate frosting.
Melt the coconut oil and coconut butter together. Add the cacao powder and mix well, removing all lumps.
Dip the cold donuts into the frosting, immediately placing them on a cooling rack to harden. This will happen quickly. If you want ot coat the other side, you can do that now.