Preheat oven to 350'F.
Mash 5 bananas to puree consistency in a large bowl (or mash in a bag for a fun task for kids to do).
Once bananas are in a large size bowl, add in (one by one) 1/3 cup oil, 2 tsp vanilla, 1/4 cup coconut brown sugar and blend together until smooth.
Slowly add in 1/4 cup brown rice flour. Continue to mix with mixer. (Tip : I like to use a slow speed to mix in flours to reduce the flour cloud and mess)
Add in 1/4 tsp salt, 1 tsp cinnamon and continue to mix.
Slowly add in the 1 1/4 cup buckwheat flour (Tip : add in on slow speed to reduce the flour cloud and mess)
Prepare loaf pan with oil, parchment paper or cooking spray (whatever you prefer)
Transfer batter into prepared loaf pan.
Bake 45 minutes or until tester comes out clean.
Remove from oven and let cool on cooling rack. *Don't forget those oven mitts!*
Enjoy! When cooled.