Preheat oven to 350 degrees. Spray a loaf pan with non-stick cooking spray. Place a piece of parchment paper in the pan and let it hang over the two sides of the loaf pan. They will act as handles to pull the loaf out.
In a large bowl, add in the ripe bananas and mash them with a fork.
Add in the vegetable oil and sugar. Mix with a hand mixer until combined.
Add in the eggs, vanilla, and sour cream. Mix until incorporated then scrape down the sides of the bowl.
Add in the baking soda, baking powder, salt, cocoa powder, and flour. Mix until incorporated.
Stir in 1 cup of the milk chocolate chips. You can use semi-sweet chocolate chips as well.
Pour the batter into the loaf pan. Sprinkle the 1 tablespoon of milk chocolate chips on top of the batter.
Place into the oven and bake for 1 hour 12 minutes or until done. Place a tooth pick into the center of the loaf and if it comes out clean or with moist crumbs, it is done. If it comes out with batter, give it an additional few minutes before testing again.
Let the chocolate chip banana bread cool completely and then pull out of the loaf pan. Cut and serve. If you cut it while it's still hot, you won't get clean slices, but it will still taste delicious.