Peel the banana and break it into chunks.
Place the banana chunks into a blender.
Add peanut butter to the blender.
Pour in the milk.
Add honey or maple syrup if desired.
Include Greek yogurt for creaminess if using.
Add ice cubes for a chilled smoothie.
Blend on high speed until smooth and creamy.
Check consistency; add more milk if too thick.
Pour the smoothie into a glass and enjoy!