In medium saucepan, combine sugar and cornstarch; blend well.
Add raspberries; stir.
Cook over medium heat until mixture boils and thickens, stirring constantly.
Remove from heat; cool to room temperature.
Line 1 1/2-quart round mixing bowl with plastic wrap.
Place 1 layer bread cubes over bottom and halfway up sides of bowl.
Pour small amount raspberry sauce over bread.
Repeat, alternating layers of bread and raspberry sauce, ending with bread on top.
Place plastic wrap over top of pudding.
Cover with plate that fits tightly inside bowl; place heavy object on top of plate to mold pudding.
To serve, remove plate and plastic wrap; unmold onto serving plate.
Remove plastic wrap.
Frost sides of pudding with swirls of whipped cream.