Measure all ingredients before blending. If the bananas are not already frozen, slice them and freeze them for about 30 minutes to achieve a thicker smoothie texture.
Pour the soy milk into the blender first to help the blades move easily. Add the frozen banana slices, frozen cherries, Greek yogurt, cocoa powder, and peanut butter.
Blend the mixture on high speed for about 45–60 seconds until the smoothie becomes completely smooth and creamy. If you prefer a thicker and colder shake, add ice cubes and blend again briefly.
Pour the smoothie evenly into two glasses. For presentation, you can garnish with fresh cherries or a light sprinkle of cocoa powder before serving.