Matrimony/Matrimonial or Date Squares, Gluten Free (Flashback Friday)

I posted this recipe a couple of years ago here but once again it is that time of year when our snowbird neighbours return home, bearing gifts. Once again they brought me a lovely container of dates and of course my mouth watered for these squares.
And so here is the repeat recipe on Flashback Friday.

Filling 

• 3 1/2 - 4 cups pitted and chopped dates
• 1 1/2 cups water 
• 2 tablespoons lemon juice 
• 2 tablespoons brown sugar 
• 1/2 teaspoon soda 

Crumbs 

• 2 1/4 cups gluten free oat flakes
• 1 1/4 cup Julie's Flour mix or your favorite gluten-free all-purpose flour
• 1 cup brown sugar 
• 1/2 teaspoon xanthan gum (if not included in your flour) 
• 1/2 teaspoon baking powder 
• 1 cup butter 
• 1 package vanilla sugar 

Method 

1. Cook the filling until it is soft, smooth and spreadable; add more water if it gets too thick.
2. Remove from stove and let cool slightly while you prepare crumbs. 
3. Mix all dry ingredients together, then cut or rub in the butter until you have uniform crumbs. 
4. Place half the crumbs into a 9 x 12 inch baking dish, pat down. 
5. Cover with date filling.
6. Cover with remaining crumbs and pat down lightly.
7. Bake at 350 degrees until lightly browned, about 30-40 minutes. 
8. Let cool completely before cutting.