Preheat oven to 400℉ and spray muffin tin with cooking spray.
Whisk first four ingredients (flour, salt, baking soda and baking powder), set aside.
Measure milk and set aside.
Use a stand mixer or a handheld mixer and cream the banana, brown and white sugar and butter.
To the wet ingredients, add the eggs, vanilla, Cointreau and zest, mixing after each addition.
Alternate adding milk and dry ingredients to the wet ingredients and mix until just combined. Start and end with dry ingredients, adding milk in-between.
Stir in mini chocolate chips.
Use muffin/ice cream scoop and add slightly overfull scoops to muffin tin.
Bake for 5 minutes at 400 then lower oven temperature to 325 for 15-20 more minutes. Muffins are done when a toothpick tester comes out clean or with a few crumbs.
Make glaze while muffins cool for a few minutes in the tray.
Rotate muffins to loosen and then transfer to a wire rack over a large piece of wax or parchment paper.
Drizzle glaze over the top of each muffin and let cool completely.