Place the whipping cream, sugar and gelatin in a sauce pan, stir well. Heat thoroughly on medium heat, stirring until gelatin is dissovled. Continue to heat through for about 5 minutes, stirring constantly. Fold in the sour cream and vanilla. Whisk gently until thoroughly blended and dissolved. Pour into one large bowl, or individual dishes. Cover by gently pressing plastic wrap over the top to seal. Chill. Refrigerate for at least 4 hours when using one large bowl. Serve plain or with topping of choice.