Heat oven to 350. Spray a 9" square baking pan w/ cooking spray. Cut 2/3 dough into 1/4"-thick slices. Press slices into bottom of pan, bake 15 mins.
In saucepan, over low heat, cook blueberries, jam and lemon juice 10 mins, or until slightly thickened, stirring occasionally.
Spread blueberry mix over crust. Using hands, crumble and sprinkle remaining dough over blueberry mix. Bake 15 mins or until golden brown. Let cool. Cut into squares. I serve w/ whipped cream or ice cream.