01 - Place Greek yogurt, milk, bananas, and ice in a blender container.
02 - Add honey, vanilla extract, and cinnamon if using desired optional ingredients.
03 - Blend on high speed until completely smooth and creamy, approximately 30–45 seconds.
04 - Taste the smoothie and add additional sweetener if needed to achieve desired flavor.
05 - Pour into serving glasses and serve right away while chilled.