To begin preparing this delectable dessert, preheat your oven to 350 degrees Fahrenheit or 175 degrees Celsius.
Next, grab a spacious bowl and combine the oats, pastry flour, salt, 1 cup of brown sugar, and baking soda. Stir the mixture until it is evenly combined, and then add the butter, ensuring that it is mixed in until the mixture becomes crumbly.Once the crumb mixture is prepared, press half of it into the bottom of a 9 inch square baking pan, making sure it is distributed evenly.
Now it's time to make the filling! Take a small saucepan and heat it over medium heat. Add the dates, water, and 1/3 cup of brown sugar and bring it to a boil. Cook it until the mixture thickens and then add in the lemon juice, stirring it in until it's fully incorporated. Remove the mixture from heat and spread it evenly over the crumb base in the baking pan.
Finally, take the remaining crumb mixture and pat it onto the top of the filling, spreading it evenly. Place the baking pan in the preheated oven and bake for 20 to 25 minutes or until the top is lightly toasted. Once it's done, let it cool before cutting it into squares.Enjoy this scrumptious dessert, and don't forget to share it with your friends and family!