Preheat the oven to 350 and prepare a loaf pan with parchment or grease. Set to the side.
In a large bowl, mash the bananas. Once they are mashed, add in the maple syrup, eggs, sour cream, and vanilla.
Mix the salt, buckwheat flour, AP flour, and baking soda into the banana mixture. Continue mixing until everything is combined.
Fold in the oil and make sure everything is fully mixed together.
If adding chocolate chips, fold them into the batter.
Pour the batter into the prepared pan and place in the oven. Bake the buckwheat banana bread for 50-60 minutes, or until a toothpick comes out clean.
Let the banana bread cool in the pan until ready to serve.