Pour boiling water to cover over dried cherries, and let stand 10 minutes; drain well, and set aside.
Combine flour and brown sugar blend in a large bowl; cut in butter with a pastry blender until crumbly. Press 2 1/2 cups crumb mixture into a lightly greased 13- x 9-inch pan.
Stir together sour cream, egg, and baking soda; add to remaining crumb mixture in bowl, stirring just until dry ingredients are moistened. Stir in cherries. Pour sour cream mixture over prepared crust in pan; sprinkle evenly with walnuts.
Bake at 350° for 20 to 25 minutes or until a wooden pick inserted in center comes out clean. Let cool completely on a wire rack, and cut into bars.