Preheat oven to 350 degrees.
In a medium bowl, combine flour, sugar and salt.
Cut in cold butter with a pastry blender until just crumbly.
Set aside 1 cup of this mixture to use as a topping later.
Lightly grease a 9 X 9" square baking pan or use parchment paper.
(An 11 X 7" pan also works fine.)
Press remaining flour mixture into the bottom of prepared pan.
Bake at 350° for 20-25 minutes or 'til lightly browned.
Spread blueberry jam over crust.
Stir in broken pecan halves with the reserved 1 cup flour mixture.
Sprinkle on top of the blueberry jam.
Bake at 350 degrees for 25-35 minutes more or 'til golden brown.
Cool 1 hour on wire rack.
Cut into sixteen bars.