Preheat the oven to 350°F with a rack in the center position. Lightly grease a 2 mini muffin pans (24 muffin cups each pan) or line with muffin papers.

In a large bowl, stir together the mashed banana with all of the remaining ingredients except any mix-ins (chips, nuts, seeds, etc.) Beat the batter thoroughly, until everything is well combined. Scrape the sides and bottom of the bowl and beat briefly to incorporate any sticky residue. Stir in the mix-ins.

Scoop the batter into the prepared pan.

Bake for about 10 to 12 minutes, until the bread feels set on the top, and a toothpick inserted into the center comes out clean, or with just a few moist crumbs (but no wet batter). If you have a digital thermometer, the bread's temperature at the center should register about 205°F.

Remove from the oven. Cool it in the pan for 5 minutes, then remove to a rack to cool completely.

Store leftover muffins, tightly wrapped, at room temperature for several days. Freeze for longer storage.