Add everything to a high-powered blender or food processor and secure the lid.
First blend on a lower speed to get everything to chop up and then blend on a high (to highest) speed, using your tamper (if you have a blender) to help mash everything to the blade for easy blending. Do this until the chocolate ice cream is completely combined, creamy, and there are no more chunks of banana.
Either serve immediately for soft serve consistency or transfer the ice cream to a freezer-safe container and freeze until completely set up.
When you’re ready to enjoy the ice cream, thaw it for a couple of minutes, scoop, and enjoy!