In 2-quart saucepan, mix soup, vermicelli and water. Cover; cook over medium heat until soup comes to a boil. Reduce heat to medium-low; cover and simmer 6 minutes, stirring occasionally, until vermicelli is of desired doneness.
Meanwhile, with 2 1/2- to 3-inch heart-shaped cookie cutter, cut shape from each toasted bread slice.
Top center of individual servings of soup with toast hearts. With aerosol can of cheese spread, pipe "I" on left side of heart and "U" on right side of heart.