1In 2-quart saucepan, mix sugar, cornstarch and salt. Gradually stir in water. Cook over medium heat, stirring constantly, until mixture thickens and boils. Boil and stir 1 minute; remove from heat. Stir in lemon peel, lemon juice, margarine and gingerroot. Press plastic wrap or waxed paper onto surface. Refrigerate about 4 hours or until chilled.
2In large bowl, gently stir sugar mixture into whipped topping.
3In large clear glass bowl, place one-third of the cake cubes. Spread one-third of the lemon mixture over cake cubes. Top with one-third of the apricots. Repeat twice. Cover and refrigerate 2 hours but no longer than 8 hours.