In a bowl, combine the flour, brown sugar and nuts. Cut in butter until mixture resembles coarse crumbs. Spread on baking sheet; bake at 400° for 20 minutes, stirring occasionally. , Remove from oven. While mixture is still hot, press into a 9-in. pie plate, forming a pie shell. Cool completely. , For cheese filling, beat cream cheese, sugar and vanilla until smooth; gently fold in whipped cream. Pour or spoon filling into cooled crust; refrigerate. , For topping, combine the sugar, cornstarch and salt in saucepan. Stir in water until smooth; add 1 cup berries. Bring to a boil. Cook and stir for 1-2 minutes or until thickened. Add butter and remaining berries. Cool; pour over cheese filling. Top with additional whipped cream if desired.