Preheat your oven to 350°F.
Grease a 9x5-inch loaf pan or line it with parchment paper.
In a large bowl, mash the ripe bananas with a fork until smooth.
Add the eggs, oil, sugar, and vanilla extract to the mashed bananas.
Stir until the wet mixture is well combined.
Add the gluten-free flour blend, baking soda, salt, and cinnamon if using.
Stir until just combined, being careful not to overmix.
Fold in chocolate chips or nuts, if using.
Pour the batter into the prepared loaf pan and spread it evenly.
Bake for 50 to 60 minutes, or until a toothpick inserted in the center comes out clean.
Let the bread cool in the pan for 10 minutes.
Remove from the pan and transfer to a wire rack to cool completely.
Slice and serve, or store as needed.