Place the rack in the center of your oven and preheat the oven to 350 degrees F. Lightly grease an 8 x 4-inch loaf pan with nonstick spray and set aside.
Mash the bananas in the bottom of a large bowl until mostly smooth.
Whisk in the egg, then the yogurt and oil.
Whisk in the brown sugar, maple syrup, and vanilla. Sprinkle the baking soda, cinnamon, and salt over the top, then stir until combined.
Gently stir in the flour until barely combined, then fold in any mix-ins.
Scrape the mixture into the prepared pan. Bake for 50 to 60 minutes, until a toothpick inserted in the center comes out clean. Check at the 35-minute mark and tent with foil if the bread is browning too quickly at the corners. Place the pan on a wire rack and let cool for 15 minutes. Remove from pan and place on rack to finish cooling completely (for neat slicing), or enjoy warm and don't worry if the slices are messy.
*If using coconut oil, be sure all of the ingredients are at room temperature and the coconut oil has cooled, or it will resolidify when it touches the cold ingredients.
TO MAKE MUFFINS: To bake this recipe as 12 muffins instead of in a loaf pan, lightly grease a standard muffin tin, then divide the batter evenly among the cups. Bake at 350 degrees F for 20 to 22 minutes, until a toothpick inserted in the center comes out clean and the muffins spring back lightly when touched.