01 - Place the sliced bananas, milk, peanut butter, cocoa powder, and honey or maple syrup (if using) into the blender jar.
02 - Add the ice cubes to the blender on top of the other ingredients.
03 - Blend on high speed until the mixture is smooth and creamy, about 30–45 seconds. Stop to scrape down the sides if needed.
04 - Taste the smoothie and add more honey or maple syrup if desired, then blend briefly to incorporate.
05 - Pour into glasses and serve immediately. Garnish with banana slices or a drizzle of peanut butter if desired.