Preheat oven to 350°F.
Grease a 9-inch loaf baking pan with your choice of olive oil, coconut oil or avocado oil.
In one mixing bowl, combine all dry ingredients including teff flour, coconut flour, baking powder, baking soda, cinnamon, and nutmeg.
In a separate mixing bowl, mash 4 bananas with a fork (or hand-mixer) and combine remaining wet ingredients and raisins (optional).
A little at a time, mix dry ingredients into the wet ingredients until smooth.
Pour batter into pre-greased loaf pan and pop in the oven.
Check after 45 minutes with a toothpick. Bake until the toothpick comes out clean.