Step 1

In a large bowl, add cream cheese, sour cream, granulated sugar, and vanilla and stir to combine.

Step 2

Carefully fold in the grapes and gently toss until evenly coated. Meanwhile, in a small bowl, mix brown sugar and walnuts.

Step 3

Sprinkle the brown sugar mixture on top of the grapes. Cover and chill at least 1 hour or overnight. Serve cold.