Preheat the oven to 325°F (160°C) with a rack in the center position. Grease a 8 x 4 inch (20 x 10 cm) loaf pan with baking spray and line with a parchment paper sling overhang.
In a medium bowl, whisk together the flour, baking soda, salt, and nutmeg. In a separate large bowl, mash the bananas with a fork or potato masher until smooth. Set aside.
In a large mixing bowl, lightly whisk the eggs. Add the oil, sugar, and vanilla extract to the bowl and whisk until smooth. Add the mashed bananas to the bowl and whisk mixture until smooth. Add the dry flour mixture to the wet ingredients. Using a stiff whisk, mix until no dry flour or bits are visible. Avoid over mixing.
Transfer the batter (it is relatively thin!) to the greased loaf pan and bake for 60 to 70 minutes or until a toothpick inserted in the center comes out clean. Immediately sprinkle the top with the turbinado sugar, distributing it evenly over the surface. It will mostly set on the bread as it cools.
Set on a wire rack and allow the banana bread to cool in the pan for 15 to 20 minutes. Use the parchment paper to lift the bread from the pan, using a knife to loosen the edges if needed.