Preheat oven to 350°F and place the rack in the center. Oil 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, avoid over mixing.
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.