Combine all the above ingredients into a blender. Add the liquid before adding the spirulina powder (to avoid powder sticking to bottom of blender/mixer).
Blend until all ingredients are completely mixed. Mixing time will depend on type of blender used. For Nutribullet/Magic Bullet approximately 45-120 seconds. For more powerful blenders this time will likely be much shorter.
Serve and enjoy or optionally chill in fridge for a few minutes.
Be careful with the spirulina powder as it tends to leave quite a mess when spilt.