Preheat your oven to 350F. Prepare the inside of a 8" x 4" loaf pan with non-stick spray.
Peel the brown bananas and place the insides in a large bowl and mash them well. You should have enough bananas to make up 1½ Cup. of If your bananas were in the freezer, make sure they are completely thawed out.
Add the rest of the wet ingredients to the mashed bananas. Whisk in the sugar and eggs first, then add the vanilla, yogurt and oil, mix well.
In a separate bowl, sift together the flour, baking powder, baking soda, and salt. Fold the sifted dry ingredients into the wet ingredients until smooth.
Pour the batter into the prepared loaf pan. Level the dough in the pan by smoothing out the top with a rubber spatula. Place into the preheated oven for 50 minutes, or until a toothpick inserted in the center comes out clean. If there still is batter on the toothpick, place back into the oven for 5-10 minutes until baked through.
Take the loaf out of the oven and let rest for 10-15 minutes before removing from the pan and slicing into it. Enjoy!