The night before, peel and slice two ripe bananas, freeze.
To make your smoothie, measure out the peanut butter, unsweetened cocoa powder, Greek yogurt, milk, honey or maple syrup, and vanilla extract.
In a blender, combine sliced bananas, peanut butter, cocoa powder, Greek yogurt, milk, honey or maple syrup, and vanilla extract.
Blend the ingredients on high speed until the mixture is smooth and creamy, about 1-2 minutes.
Add the ice cubes to the blender and blend again until the smoothie is thick and frosty, about 1 minute.
Taste the smoothie and adjust the sweetness by adding more honey or maple syrup if needed. Blend briefly to combine.
Pour the smoothie into a glass and garnish with a slice of banana or a sprinkle of cocoa powder if desired.