01 - Place frozen banana slices, milk, cocoa powder, peanut butter, maple syrup or honey, vanilla extract, and salt in a blender.
02 - Blend mixture on high speed until completely smooth and creamy.
03 - Taste and add more sweetener if desired, then blend briefly to incorporate.
04 - Pour smoothie equally into two large glasses.
05 - Top each glass with whipped cream, chocolate shavings, or crushed peanuts as desired. Serve immediately.