In a large mixing bowl, completely dissolve the cherry Jello in 1 cup of boiling water. Allow it to cool to room temperature.
Mix with Cherry Pie Filling:
Stir the cherry pie filling into the dissolved Jello. Make sure it's well incorporated.
Add Pineapple and Marshmallows:
Add the drained crushed pineapple and mini marshmallows to the mixture. Stir until evenly distributed.
Fold in Whipped Topping:
Gently fold in the whipped topping until the mixture is uniform in color and no streaks remain. If using, stir in the chopped pecans or walnuts.
Chill:
Pour the mixture into a serving dish or individual dessert cups. Cover and refrigerate for at least 4 hours, or until set. It’s best if left to chill overnight.
Serve:
Once set, the Pink Cherry Jello Fluff is ready to serve. Garnish with additional whipped topping, maraschino cherries, or a sprinkle of chopped nuts before serving if desired.