Jackie's Grape Salad

My sister had this salad at one of her bridal showers. I've tweaked it a little, just for my taste.

4 lbs red or black grapes
8 oz cream cheese
8 oz plain yogurt
1/2 c sugar
1 t vanilla
1/2 c brown sugar
1/2 c chopped pecans

Wash grapes, de-stem, and set aside to dry. Blend first four ingredients in a food processor until smooth. Mix grapes and sauce in a bowl.
Half an hour before serving, sprinkle on brown sugar and pecans and mix in.