In a saucepan, combine dates, sugar and water. Cook, stirring frequently, until thick. Stir in nuts if desired.
Meanwhile, in a bowl, sift together flour, salt and baking soda. Add oats and brown sugar. Cut in butter until crumbly. Add water and mix lightly. Press half into a greased 13x9-in. baking pan. Spread date mixture on top. Cover with remaining oat mixture; pat lightly.
Bake at 350° for 35-40 minutes or until lightly browned.