In a small bowl, sprinkle unflavored gelatin over cold water; let stand for 1 minute. In a small saucepan, combine half-and-half and sugar. Cook and stir just until mixture comes to a simmer. Remove from the heat; stir into gelatin until dissolved.
In a large bowl, beat cream cheese until smooth. Fold in gelatin mixture. Stir in vanilla. Pour into a 6-cup mold coated with cooking spray. Refrigerate until set but not firm, about 45 minutes.
In a small bowl, dissolve raspberry gelatin in boiling water. Stir in raspberries until blended. Carefully spoon over cream cheese layer. Cover and refrigerate at least 4 hours.
Unmold onto a serving plate; garnish with fresh berries if desired.