1. Preheat the oven to 350°F (175°C), and butter a 4x8-inch loaf pan.
2. In a mixing bowl, mash the ripe bananas with a fork until completely smooth.
3. In a separate bowl, cream together butter, white sugar and brown sugar. Stir in eggs, vanilla extract and mashed bananas until well blended.
4. In a small bowl, stir flour, baking powder, baking soda, salt and cinnamon.
5. Stir chocolate chips and flour mixture into banana mixture; stir just to moisten. Pour batter into greased loaf pan.
6. Bake for 55-65 minutes. until a toothpick inserted into center of the loaf comes out clean
Note: if after 30 minutes in the oven, the bread turns too brown, cover with foil for the rest of baking.