Wash the grapes and cut off the stems. Complete drying
Cream cheese should be thoroughly smoothened up in a big bowl using a handheld mixer. Add vanilla, sugar, and sour cream. Mix at medium speed for two minutes.
As soon as the grapes are added, carefully fold them into the cream cheese mixture by hand. Until you are ready to serve, cover and chill.
Add pecans and brown sugar to the grape salad just before serving.