While the coconut oil is not strictly necessary, it makes the banana bread as rich and moist as oil. And because it's solid at room temperature, it provides the slow-melting richness of butter without making the loaf heavy and wet, or greasy.
An AlohaDreams.com recipe
Peel 4 bananas (you should have about 12 ounces) and in a medium bowl mash bananas with 4 ounces yogurt, 2 eggs, 2 teaspoons water and 1 teaspoon vanilla. NOTE: If bananas are under-ripe, cover bowl with plastic and let mixture stand 30 minutes.
In the bowl of a stand mixer fitted with a paddle attachment, add 240 grams flour, 1 cup sugar, 1/4 teaspoon table salt, 1 teaspoon baking powder, 1 teaspoon baking soda, 1/2 teaspoon cinnamon, and 3/4 cup solid coconut oil. Mix on low until mixture becomes a mealy powder. Add banana mixture and continue mixing only until no more flour is visible. Fold in nuts and scrape into prepared pan(s), spreading into an even layer.
Bake until risen and golden brown - about about 50 minutes for two smaller loaves (or 70 minutes for a large loaf). Bread is done when it reaches an internal temperature of 206°F.
When done, set the loaf, still in the pan, on a wire cooling rack. Let cool for 10 minutes — this helps the loaf solidify and makes it easier to remove from the pan.
To keep this simple, you can substitute 1 stick of butter (salted or unsalted) for the coconut oil and omit the yogurt entirely if you wish.