Preheat the oven to 325 degrees.
Spray an 8 x 4-inch loaf pan with nonstick cooking spray and set aside.
In a blender, combine the dates and the water. Blend until smooth.
Add the date mixture to a medium-sized bowl.
Add the sugar, butter, egg, salt, and vanilla. Either beat by hand or using a mixer, mix on medium speed until thoroughly mixed, scraping down the bowl as needed.
In a small bowl, combine the flour, baking powder, and salt. Stir.
Add the flour mixture and mix until combined.
Stir in the walnuts. Pour the batter into the prepared loaf pan.
Bake at 325 degrees for 60 to 70 minutes or until a skewer inserted in the center comes out clean, with no visible amounts of batter. If crumbs are attached, that's ok!
Remove the pan immediately from the oven and cover with foil, making sure the foil doesn't touch the top of the loaf.
Cool for 1 hour. Remove the foil and remove the loaf from the pan. Slice and enjoy!