Preheat the oven to 350°F (175°C). Grease 3-4 mini loaf pans or line them with parchment paper.
Mash the bananas in a large bowl until smooth.
In a separate bowl, whisk together the flour, baking soda, baking powder, salt, and cinnamon.
In a mixing bowl, beat together the butter and sugar until light and fluffy.
Add the eggs, one at a time, beating well after each addition. Then stir in the vanilla extract.
Gradually add the dry ingredients into the wet mixture, mixing gently until just combined.
Pour the batter into the prepared mini loaf pans and smooth the tops.
Bake for 25-30 minutes or until a toothpick inserted into the center comes out clean.
Once baked, transfer the loaves to a wire rack to cool completely before serving.