Preheat oven to 350. Prepare a 9"x13" pan with cooking spray; set aside. To prepare crust, combine cake mix, cracker crumbs, and margarine in a mixing bowl. Mix until crumbly. Press into bottom of prepared pan. Bake for 15 minutes or until lightly browned. Meanwhile, to prepare filling, combine cream cheese, sugar, eggs, and lemon juice. Mix until smooth. Spread jam over baked crust. Sprinkle with blueberries. Pour cream cheese mixture evenly over blueberries in pan. Bake for 30 minutes, or until set. Cool. Chill three hours before serving.