Preheat oven to 350 degrees. Line your 9x5 loaf pan with parchment paper, greasing the areas that are not covered with the paper. If not using parchment paper, generously grease the loaf pan.
Mix together the flour, baking soda, baking powder, salt and cinnamon in a bowl. Set aside.
In a mixing bowl, beat the butter and sugar together until light and fluffy. Add in the eggs on at a time, beating after each one is added. Add in the mashed banana, milk and vanilla.
Combine the dry ingredients to the banana mixture. Mix just until combined. Add in the chocolate chips.
Pour the batter into the prepared pan.
Bake until toothpick comes out clean, about 60 minutes. Cool slightly before serving.