Heat 1 3/4 C. water and 3/4 C. sugar to boiling, stirring occasionally. Add rhubarb. Simmer uncovered until rhubarb is tender, about 10 min. Mix 1/4 C. water and the cornstarch, stir into rhubarb. Heat to boiling, stirring constantly. Boil and stir 1 min. Stir in vanilla extract. Pour into serving bowl or dessert dishes. Cover and refrigerate. Beat whipping cream and the 2 T. sugar in chilled bowl until stiff. Pipe through decorators tube or spoon onto pudding.