Combine flour, sugar, brown sugar and salt in a large bowl. Cut in shortening, vanilla and maple flavoring until mixture resembles course crumbs. Stir in coconut. Set aside one third of mixture. To the remaining two thirds, add egg and stir until combined.
Put dough into a lightly greased 17x11 jellyroll pan. Spread carefully with date filling. Sprinkle walnuts, then reserved crumb mixture.
Bake at 350 degrees for 24 to 28 minutes or until lightly browned. Cut into bars when cooled.
Combine dates, brown sugar, corn syrup, alt and water in medium saucepan. Heat over medium heat, stirring often, until dates are soft and mixture has a pastry like consistency. Cool.