Mix sugar and cornstarch in medium saucepan. Gradually add water, stirring until well blended. Bring to boil on medium heat, stirring constantly; boil 1 min. Remove from heat. Add dry gelatin mix; stir 2 min. until completely dissolved. Cool.
Add fruit to gelatin mixture; pour into crust.
Refrigerate 3 hours or until firm. Serve topped with COOL WHIP.