01 - Place bananas, Greek yogurt, milk, and sweetener (if using) into blender container.
02 - Add vanilla extract, cinnamon, seeds, and ice cubes to blender.
03 - Blend on high speed until completely smooth and creamy, approximately 45-60 seconds.
04 - Taste smoothie and add more milk for thinner consistency or honey for additional sweetness as desired.
05 - Pour evenly into two glasses and serve right away while chilled.