Preheat the oven to 350°.
Combine almond flour, gluten-free flour blend, 2 tbsp Truvia, flaxseed meal, and salt in a large bowl.
Cut cold butter or margarine in small chunks and drop into the bowl of flour.
Cut butter into the flour blend using either a pastry blender or a fork (or hands). a. The mixture will be crumbly. b. Try to get the butter or coconut oil to pea-sized pieces Add 1 tbsp cold water at a time, until the mixture starts to just come together.
In a separate bowl, combine the fresh or frozen blueberries with 1 tbsp Truvia, ½ tbsp corn starch and 1 tbsp lemon juice, mix together until combined.
In a 9”x9” brownie pan, add a little over half of the flour mixture and press down for the crust.
Bake this crust for 7-10 minutes.
After the 10 minutes is up, take out of the oven and add the blueberries, spreading out evenly in the pan, using caution as the pan will be hot.
Add the chopped nuts to the remaining flour mixture, then crumble this blend on top of the blueberries.
Bake for an additional 25-30 minutes, or until slightly brown on top.
Let cool completely before slicing.