Preheat the oven to 350 degrees and line a 9x5 loaf pan with parchment paper.
Mash the bananas in a mixing bowl. Whisk in the eggs, vanilla extract and melted coconut oil until well-combined (wet ingredients).
In a separate bowl, stir together the gluten-free flour, baking soda, sea salt, coconut sugar, and cinnamon until combined (dry ingredients).
Pour the dry mixture into the mixing bowl with the wet mixture and stir until the batter is incorporated. If adding chocolate chips and/or chopped walnuts, do so here.
Transfer the batter into the parchment-lined loaf pan.
Bake on the center rack of the preheated oven for 50 to 60 minutes, or until the top is golden brown.
Remove bread from the oven and allow it to cool 30 minutes before slicing and serving.