If using fresh bananas, peel and slice them. If using frozen bananas, measure them out directly.
In a blender, combine bananas, peanut butter, rolled oats, cacao powder, honey, and milk.
Blend on high until smooth and creamy. If using fresh bananas, add ice cubes for a colder, thicker texture, and blend again until the desired consistency is achieved.
Taste the smoothie and add more honey if desired. Blend briefly to incorporate.
Pour the smoothie into two glasses and serve immediately.