Before beginning, ensure the bananas have been fully frozen. Slice each banana into chunks, ideally freezing them individually on a lined baking sheet to prevent clumping.

In a blender, place the frozen banana chunks, peanut butter, and cocoa powder. Begin pulsing at low speed to break down the bananas, then blend on medium-high until smooth. You may need to stop occasionally to scrape down the sides or add a small splash of water if the mixture is too thick.

Once the mixture has reached a creamy, smooth consistency, transfer it to a serving bowl. Sprinkle with chopped pecans and drizzle with chocolate syrup, if desired, for added flavor and texture.

If a soft-serve texture is preferred, serve immediately. For a firmer ice cream, place the mixture in an airtight container and freeze for an additional hour before scooping.