01 - Place the banana, milk, peanut butter, cocoa powder, and sweetener (if using) into the blender pitcher.
02 - Pour in the vanilla extract and add ice cubes for extra creaminess and chilled temperature.
03 - Process on high speed until completely smooth and creamy, approximately 45 to 60 seconds.
04 - Taste the mixture and add additional sweetener if needed to achieve desired flavor balance.
05 - Divide evenly between two glasses and serve right away for optimal texture and temperature.