1) Preheat the oven to 375°F. Lightly grease 12 muffin cups, or line them with baking papers.
2) In a large bowl, stir together the oil or melted butter and sugar.
3) Add the eggs and mix until well blended.
4) Add the mashed bananas, baking mix, baking soda, cinnamon, and nutmeg, mixing until blended.
5) Stir in the chocolate chips.
6) Scoop the batter into the prepared muffin cups; a ¼-cup muffin scoop works well here. Sprinkle the tops with sparkling sugar, if desired.
7) Allow the batter to rest for 10 minutes before baking.
8) Bake for 18 to 22 minutes, or until the top springs back and a toothpick inserted into the center comes out clean.
9) Allow the muffins to cool for 10 minutes in the pan, then turn out onto a rack to cool completely.
Yield: 12 muffins.