Add all the ingredients to the blender with half of the ice cubes. Blend until combined.
Add the chocolate chips and remaining ice cubes. Blend until smooth, or keep some chocolate chips intact.
Notes
Feel free to use your blender's smoothie button and let it do its thing while you clean up.
Besides using a powerful blender, you can add more liquid if the mixture is too thick to blend smoothly. Start at a low speed, gradually increase to high, then end at a low speed to keep the smoothie from getting foamy.
Instead of a frozen banana, you can also thicken your healthy peanut butter cup smoothie with avocado! Don't worry; you won't be able to tell it's there.