Begin by combining the softened cream cheese, sour cream, sugar, and a touch of vanilla essence in a mixing bowl. Use a hand mixer to create a velvety, seamless blend.
In a separate, smaller bowl mix the walnuts together with the brown sugar.
Pour the grapes into the cream cheese mix and use a spoon to mix the grapes into the creamy mixture.
Scoop the grapes into a serving bowl and sprinkle on the nut and sugar mix.