In a small bowl, combine flour and confectioners' sugar; cut in the butter until crumbly. Press into a greased 13-in. x 9-in. baking dish. Bake at 350° for 15-20 minutes or until edges are lightly browned.
In a large bowl, beat cream cheese until smooth. Add milk and lemon juice. Pour over crust. In a small bowl, combine the cornstarch and brown sugar. Stir in the cranberry sauce until combined. Spoon over cream cheese layer. For topping, combine the flour and brown sugar in a bowl; cut in butter. Fold in walnuts. Sprinkle over filling.
Bake at 325° for 40-45 minutes or until topping is golden brown. Cool on a wire rack. Cover and refrigerate for 3 hours before cutting.