Preheat the oven to 350 F. Mix together the all-purpose flour, baking powder, baking soda, salt, cinnamon, and chocolate chips. Set aside.
In another bowl, mash the bananas.
Add an egg, sugar, melted butter, and vanilla extract to the mashed bananas. Beat using an electric mixer on a low speed until combined.
Add the dry ingredients to the wet. Gently stir just until combined.
Line a muffin tin with 12 paper liners. Divide the banana chocolate chip muffins batter evenly between them. Bake in the preheated oven for 15-20 minutes or until ready. Check the readiness using a toothpick inserted in the center, if it comes out clean - muffins are ready.
Remove from the oven and let them cool slightly in a muffin tin. Then, transfer to a cooling rack. Enjoy!