Preheat oven to 350 degrees. In a large bowl, whisk flour, sugar, baking powder, baking soda and salt. Add chocolate chips.
In a separate bowl, whisk together bananas, butter, milk, vanilla and eggs. Pour over the flour mixture and stir until blended. Grease a 9×5 loaf pan with butter and sprinkle with cinnamon and sugar. Pour mixture into the loaf pan.
Bake for 50 to 60 minutes, until the crust is golden brown and a toothpick comes out clean. Let cool in pan for 15 minutes before turning out onto a rack or serving plate.