Preheat oven to 350°F. Do not use convection. Spray a 9x5 inch loaf pan with non-stick spray and line the long side with a strip of parchment that extends past the rim.

In a large bowl, whisk together the mashed bananas, maple syrup, warm coconut oil, and vanilla extract. Whisk vigorously until the mixture is smooth and emulsified.

In a separate bowl, whisk together the oat flour, cocoa powder, baking powder, baking soda, and salt. Add the dry ingredients to the wet and whisk until just combined.

Fold in the chocolate chips. Pour the batter into the prepared pan. Top with additional banana slices or chocolate chips if desired.

Bake 45 to 55 minutes, until a toothpick or cake tester comes out clean. When testing for doneness, look closely at the toothpick: a streak from melted chocolate chips looks different from wet batter. If the streak smears cleanly and the rest of the toothpick is dry, the bread is done.

Cool in the pan for 8 to 10 minutes, then lift out using the parchment and transfer to a wire rack to cool completely before slicing with a serrated knife.