Grease a square 8" or 9" cake pan well, or line with parchment, and preheat your oven to 350 degrees.
In a large bowl, combine the oats, flour, brown sugar and 1 teaspoon each of salt and baking soda.
Melt the butter and pour it over the dry ingredients. Toss just until combined. Dump about half of the mixture into the pan and press it down to make an even layer.
In a medium sized saucepan over medium high heat, place the dates, water, and remaining baking soda and salt and bring up to a boil. Reduce heat and allow to simmer for about 5 minutes, or until the dates are softened. Mash them up a bunch with the back of a spoon to make them a bit smoother. Pour this date mixture overtop of your base layer in the pan.
Sprinkle the remaining oat mixture over the date layer and press it down lightly.
Bake in preheated oven for 30 minutes, until golden brown on top.