Preheat the oven to 350°F (175°C). Grease a 9×5 inch loaf pan with butter or non-stick spray.
In a large mixing bowl, combine the mashed bananas, granulated sugar, and melted butter. Mix well.
Add the eggs one at a time, beating well after each addition, then stir in the vanilla extract.
In a separate bowl, whisk together the all-purpose flour, baking soda, salt, and ground cinnamon.
Gradually add the dry ingredients to the banana mixture, stirring just until combined. Do not overmix.
Pour the batter into the prepared loaf pan and smooth the top with a spatula.
Bake in the preheated oven for 60 minutes, or until a toothpick inserted into the center comes out clean.
Remove from the oven and let the bread cool in the pan for 10 minutes.
Transfer the banana bread to a wire rack to cool completely before slicing.