Heat the oven to 350 F. Lightly grease 12 standard muffin cups. I used parchment paper liners which are larger in size and sprayed them lightly with oil. You may need additional muffin cups if you use all the add-ins.
In a small pan bring the banana liquid to a simmer and continue to cook until the liquid is reduced in half -- to about ⅓ cup. Let cool.
In a medium-sized mixing bowl, beat together the butter and sugar till smooth.
Beat in the mashed banana, then the egg, the flavorings, and the cooled reduced banana liquid.
In a separate bowl whisk the baking powder, baking soda, salt, and flours until it is thoroughly mixed. Add it to the wet ingredients and stir till smooth. If the mixture has a lot of lumps, beat at a higher speed until they've nearly disappeared.
Stir in the bittersweet chocolate chips, walnuts, and cinnamon chips.
Heap the thick batter into the prepared muffin cups, mounding them quite full. I used a large scoop to fill the muffin cups.
Sprinkle the tops of the muffins with coarse white sparkling sugar.
Bake the muffins for 25-30 minutes, until a cake tester inserted into the center of one of the middle muffins in the pan comes out clean.
Remove the muffins from the oven, and tilt them in the pan to cool a bit; this will prevent their bottoms from becoming soggy. As soon as you can safely handle them, transfer the muffins to a rack to cool completely.