Preheat oven to 400°; line rimmed baking pan with parchment paper. Place baguette slices in single layer on prepared pan; brush both sides with oil and bake 10 minutes or until crisp. Cool crostini completely. Makes 32 crostini.
In medium bowl, with mixer on medium-high speed, beat cheese and cream 2 minutes or until incorporated, scraping down bowl occasionally. Makes about 1 cup cheese mixture.
Spread crostini with cheese mixture; top with grapes and walnuts, and garnish with chives, if desired. Makes 32 crostini.