01 - Add the banana, milk, peanut butter, cocoa powder, honey or maple syrup, vanilla extract (if using), and ice cubes to a blender container.
02 - Blend on high speed until completely smooth and creamy, approximately 30-60 seconds, ensuring no lumps remain.
03 - Taste the smoothie and add additional sweetener if desired, blending briefly to incorporate.
04 - Pour into two glasses and serve right away while chilled and frothy.