Preheat the oven to 350F. Grease a standard loaf pan, OR several small loaf pans, OR muffin tin. Set aside.
In a medium mixing bowl, add flour. Then sift in the cocoa powder. Add the baking powder, baking soda and salt. Whisk well.
In a bowl or 1 cup measuring cup, mash the banana until the consistency is essentially a purée. Using a fork works really well.
Add the mashed banana into the dry ingredients. Then add the oil, brown sugar, granulated sugar, and milk. Stir with spoon until all ingredients are combined.
Finally add the chocolate chips, gently mixing into the batter.
Pour into the prepared loaf pan and bake for about 40-50 minutes.** Time will vary immensely depending on what type of pan you use. If making muffins, set timer for 20-24 minutes.
Test doneness with a tooth pick, or digital thermometer. Internal temperature should be at least 205F.
Allow to cool slightly before cutting into the bread.