In a large bowl, add flour, baking soda and salt; whisk until blended. Add butter and using a pastry cutter, combine with flour. Add brown sugar and rolled oats; stir until mixture is crumbly (don’t over mix). Scoop half of the flour-oat mixture into an 8 X 8 lightly buttered baking dish. With the back of a spoon compact it by pressing down gently; set aside. Preheat oven to 350ºF.
In a small saucepan, combine dates, water and vanilla extract. Stir and bring to a boil. Reduce heat to medium-low and gently simmer until the dates are soft, stirring often; while cooking, mash them. Remove from the heat and cool off for about 5 minutes.
Spoon date mixture on bottom crust and level it out with a spatula. Add the remaining oat mixture and press down gently. Transfer to the preheated oven and bake for 25 minutes. Cool completely before cutting into squares.