Place bananas, almond milk, almond butter and cocoa powder into a food processor or high speed blender.
Pulse/process until smooth and creamy. You may need to turn off the motor and stir the mixture a couple times while processing.
Add in cacao nibs or chocolate chips (if using) and pulse once more. Spoon ice cream in to a bowl and enjoy! If you want to be able to scoop the ice cream you can place it in the freezer for 2 hours so it's solid enough to scoop.