Using a hand mixer, blend together cream cheese and sour cream until smooth. Add in vanilla and sugar and whip until incorporated. Add in grapes and gently fold into cream cheese mixture. Cover bowl with plastic wrap and chill in the refrigerator for 1 hour.
Remove from refrigerator and put in serving bowl. Sprinkle on brown sugar and pecans. Serve. **Can be stored in fridge for up to 3 days.