Preheat the oven to 350° F and line a loaf pan with parchment paper or spray with nonstick cooking spray.
In a large bowl, or bowl of a stand mixer, cream together butter and sugar until fluffy. Add eggs and milk and mix to combine.
Add in flour, baking powder, baking soda, salt, and cinnamon and mix to combine. Stir in very ripe bananas, mashing slightly while mixing, just till incorporated.
Add 1 cup of the chocolate chunks and stir in.
Pour batter into prepared loaf pan and sprinkle top with the remaining 1/4 cup chocolate chunks.
Bake at 350° F for 45-55 minutes or until a toothpick inserted in the center comes out almost clean with just a few crumbs.
Let cool in the pan for 10 minutes then turn out onto wire cooling rack to cool completely.