Preheat your oven to 400°F (200°C). Line a 12-count muffin pan with cupcake liners and set aside.
In a large bowl, combine the wet ingredients until fully mixed.
Add the dry mixture to the bowl with the wet mixture. Mix until thoroughly combined.
Using a large ice cream scoop or a spoon, divide half of the batter into your muffin pan, filling each cup about ¾ full (this will yield 6 plain banana muffins).
Add the chopped chocolate coated with dry ingredients to the remaining batter and mix well. Divide this batter into the muffin pan, filling each cup about ¾ full. Top each muffin (the ones with chopped chocolate) with additional chopped chocolate or chocolate chips.
Bake in the preheated oven for 18-23 minutes or until a toothpick inserted into the middle of the muffins comes out clean. Leave the muffins in the pan for 5 minutes before enjoying.