Preheat oven to 350 degrees. Cream butter and brown sugar in a large bowl until light and fluffy. Add flour and nuts. Blend until the mixture resembles crumbs and set aside 3/4 cup, press the remaining mixture into the bottom of an 8" square pan. Bake for 15 minutes. Combine the sugar and the cream cheese in a medium bowl and beat until smooth, add the egg, milk, lemon juice and vanilla, beating well. Spread the cream cheese mixture over the baked crust. Sprinkle the reserved 3/4 cup of crumbs over the top. Bake for 25 minutes. Cool for 1 hour in the refrigerator and cut into bars.
Start this project early in the day, for the next day.
Wash all grapes, pick them off the vine, and dry them on towels. They must all be absolutely dry.
Cream together cream cheese, sour cream, vanilla and sugar.
Add dry grapes and mix gently. Put in 9 X 13 pan.
Mix topping together. Put on top, spreading over all.