Combine flour and coffee granules in a large bowl. Add brown sugar, cinnamon, and salt; stir well. Cut in butter with a pastry blender until crumbly. Press half of crumb mixture into a lightly greased 9" square pan; set aside.
Combine sour cream and baking soda, stirring well. Add to remaining crumb mixture, stirring just until dry ingredients are moistened. Add egg, stirring gently to combine. Pour sour cream mixture over crumb crust in pan; sprinkle with pecans.
Bake at 350° for 45 minutes. Cool and cut into squares.