Preheat oven to 375F. Grease an 8-in square baking dish with cooking spray or butter. Line with parchment paper leaving some overhang. Combine dates with water in a small pot. Bring to a boil, reduce heat and simmer gently 5 min or until dates are very soft and pan is almost dry. Remove from heat and stir in lemon zest and juice. Combine oats, flour, brown sugar and baking soda in a large bowl. Add butter pieces and mix with pastry cutter on your hands until mixture forms crumbs. Spoon half of this mixture into prepared pan. Press it very well and evenly into the pan. Top with date mixture, spreading it out evenly. Sprinkle evenly with remaining oat mixture.  Bake 45 to 50 min or until golden. Cool completely on a rack before slicing into squares.