In large saucepan, mix Jello ... aside and let cool. When cooled, add buttermilk, nuts, and Cool Whip. Mix until well blended, ... refrigerate for 1-2 hours.
Mix Jello according to directions, ... allow to partly congeal. Mix banana, pineapple, and nuts into Cool Whip. Blend this into Jello. Allow to congeal again before serving.