In a blender, combine the cranberry juice, sugar and 5-1/3 cups raspberries; cover and process until blended. Strain and discard seeds. Stir in 1-1/3 cups sour cream. Cover and refrigerate for at least 2 hours.
To serve, pour 1/4 cup of soup into 12 cordial glasses. Top each with a raspberry and 1/2 teaspoon sour cream.