Slice banana into 12 even slices. Cover a tray with parchment or wax paper. Place banana slices on tray, forming a circle with the bananas, and placing one banana slice in the center of each circle.
Mix the rest of the ingredients together in a small bowl until well combined and smooth chocolate peanut butter sauce forms. Drizzle sauce evenly over banana slices, spreading evenly to coat banana slices. Place tray in freezer for at least 4 hours or overnight. Remove from freezer about 5 minutes before you are ready to serve and enjoy!