Blue Ridge Blackberry Lemon Bars

Heat oven to 325 degrees F. In a large mixing bowl toss together oats, flour, brown sugar, walnuts, cinnamon, nutmeg, lemon zest and salt until well blended. Sprinkle mixture with lemon juice, then with a pastry blender or two knives, cut in the butter pieces until mixture is crumbly. Spray a 9 x 13 inch baking pan with non-stick cooking spray. Reserve 2 cups of the oat mixture, then sprinkle remainder in pan, pressing with fingers to form a crust. Bake for about 10 minutes, or until set. Let cool slightly, then spread blackberry jam evenly over crust. Sprinkle evenly with reserved oat mixture, pressing down gently. Return to oven and bake for 15 to 20 minutes, or until crust is golden brown.