Preheat the oven to 325 degrees F. Butter a 9 x 5 inch loaf pan.
Cream the butter and sugar in a large mixing bowl until light and fluffy. Add the eggs, beating well after each addition.
Mash the bananas with a fork in a small bowl. Mix in the milk and cinnamon. Add optional nuts or chocolate chips.
In another bowl, swift together the flour, baking soda, baking powder, and salt.
Add the banana mix to the creamed mixture and stir until combined. Add dry ingredients and mix until flour disappears.
Pour batter into prepared pan and bake 60 - 70 minutes, until an inserted toothpick comes out clean. Set aside to cool for 20 minutes. Remove from pan and invert onto a rack to cool completely.