Gluten Free Blueberry Lemon Bars.

Preheat oven to 350 degrees F. Grease a 9×13 pan and line with parchment paper.
Zest two lemons. Pour 1 ½ cups of sugar into a bowl and work the lemon zest into the sugar with the back of a spoon.
Combine lemon sugar, gluten free flour, salt and butter and mix on medium speed until forms large crumbs.
Set aside 1 ½ cups of the crust mixture to use as the topping. Place the rest of the mixture into the bottom of the pan and press flat.
Bake crust for 12 to 15 minutes, or until golden brown - this may take longer with your gluten free flour blend. Let crust cool while you prepare the filling.
For filling: whisk the eggs in a large bowl. Add sugar, sour cream, lemon juice, flour, and salt. Add berries and pour the mixture evenly over the crust.
Sprinkle reserved topping over filling.
Bake at 350 degrees F for 45 to 55 minutes, or until topping is lightly browned.