Preheat oven to 350°F and place the rack in the center. With a neutral oil or nonstick cooking spray, grease a 9″x5″ loaf pan and set aside.
In a large mixing bowl, smash your bananas. Add the olive oil, maple syrup, greek yogurt, eggs, and vanilla extract. Stir to combine. Next, add in the all-purpose flour, whole wheat flour, baking soda, and sea salt. Mix just until the batter combines.
Pour the batter into the prepared baking dish and bake until golden brown and a toothpick/cake tester comes out clean, about 60 minutes. Cool in the pan for 10 minutes. Finally, turn the loaf out of the pan to cool completely.