Drain pineapple, reserving juice.
In a large bowl, stir together pineapple chunks and marshmallows. Cover and chill in the refrigerator for up to 24 hours.
Meanwhile, for dressing, in a small saucepan, stir together the sugar and flour; add the reserved pineapple juice, the vinegar, and egg.
Cook and stir over medium heat just until mixture bubbles; reduce heat. Cook and stir for 2 minutes more.
Transfer the mixture to a small bowl. Cover the surface with plastic wrap and chill in the refrigerator for 2 hours.
To serve, add chilled dressing, apples, dessert topping, cherries, and peanuts to marshmallow mixture; stir to mix well. Makes about 20 side-dish servings.