Preheat oven to 350°F and line an 8×4 inch loaf pan with parchment paper. Set aside.
In a large bowl, make the flax egg by combining the ground flaxseed and water. Stir and set aside for 5 minutes to thicken.
In a medium bowl, add the oat flour, baking powder, baking soda, cinnamon, and salt. Whisk until well combined.
In the bowl with the flax egg, add the ripe bananas. Mash until smooth. Add the coconut oil, granola butter, coconut sugar, and vanilla extract. Whisk until well combined.
Add the dry to the wet. Use a spatula to mix until just combined. Don’t overmix. Fold in the chocolate chips.
Pour batter into the prepared pan. Sprinkle extra chocolate chips on top. Bake for 45-50 minutes. It is done when a toothpick inserted in the center comes out clean. Let it cool in the pan for 10-15 minutes. Then carefully lift the bread out and place onto a wire rack to cool completely. Slice and enjoy! Store leftovers in an airtight container on the counter for 3 days. It tastes even better the next day!