Rinse and dry the grapes completely. Slice each one in half for better texture and even mixing.
In a large mixing bowl, beat the softened cream cheese with a hand mixer until fluffy and smooth.
Add the sour cream, sugar, and vanilla extract, and continue beating for 2 minutes until fully combined.
Gently fold the grapes into the creamy mixture using a spatula until evenly coated.
Transfer the salad to a serving bowl, cover with plastic wrap, and refrigerate for at least 15 minutes (or up to 24 hours).
Just before serving, sprinkle chopped pecans and brown sugar evenly across the top.
Serve chilled and enjoy every creamy, crunchy bite!