In mixing bowl beat together sugar, cornstarch and eggs until smooth.
In double boiler mix milk and egg mixture; heat until mixture is thickened, stirring constantly. Add sherry, if desired. Set aside to cool.
Whip the cream and set aside.
Slice cake into 1/2 inch slices. Arrange layers in deep crystal bowl or a trifle bowl, beginning with cake slices, then spreading preserves, layer of custard and a layer of whipped cream. Repeat until all ingredients are used. Chill about 6 to 8 hours.
Makes: 4