Combine dates, water, and maple syrup in a heavy saucepan on medium heat.
Bring to a boil and cook about 12 minutes, stirring frequently, until most of the liquid is absorbed and it looks like jam. Stir in the rind and remove from heat to cool completely.
Cream the sugar and butter with a mixer at medium speed until smooth. Combine flour, oats, baking soda, and salt, then stir into sugar mixture. (It will become crumbly) Press 2 cups flour mixture into bottom of a 13 x 9-inch baking pan coated with cooking spray. Spread date mixture on top, then sprinkle with remaining flour mixture. Bake 20 minutes or until golden brown. Cool completely in pan on a wire rack.