Preheat the oven to 400ºF. Line a muffin pan with muffin liners and set aside.
In a blender, combine all of the wet ingredients and blend until completely smooth.
In a medium mixing bowl, mix together all of the dry ingredients. Pour in the banana mixture and stir well until completely combined. Fold in the chopped chocolate until evenly distributed.
Transfer the batter to the prepared muffin pan, using a 1/4 cup measure for each muffin.
Bake for 20 minutes or until a toothpick inserted into the middle of the muffin comes out clean.
Allow to cool for about 10 minutes in the pan before transferring to a cooling wrack. The muffins will keep for up to 4 days in an airtight container.