Preheat the oven to 350 degrees F. and adjust the oven rack to the middle position. Butter a loaf pan.
In a small saucepan, melt the butter and coconut oil; cool slightly. In a large mixing bowl, whisk together the flour, sugar, salt and baking soda. In a separate medium bowl, stir together the mashed bananas, zucchini, buttermilk, eggs, melted oils and vanilla. Pour the wet ingredients into the dry ingredients and gently stir until just blended.
Pour the batter into the loaf pan and bake for 50 to 60 minutes or until golden brown and a toothpick pressed into the center comes out with a few moist crumbs attached. Cool for 10 minutes and then run a knife around the outside to loosen the edges. Turn loaf out onto a cooling rack and cool before serving.
Notes
Prepare this bread with all organic ingredients, or feel free to make substitutions if you prefer.