Mash the bananas and add the buttermilk or milk, egg, oil, vanilla, and honey. Mix well.
In a separate bowl, mix together the flour, cocoa, baking powder, baking soda, cinnamon, and salt.
Add the flour mixture to the banana mixture and stir just until blended. Stir in chips if desired.
Scoop into muffin pans that have been coated with non-stick spray.
Bake in a 350 degree oven. 10-12 minutes for mini muffins, and 15-18 minutes for regular muffins. They are done when you insert a toothpick and it comes out clean.
Cool slightly, then remove from pans and finish cooling on a rack.