Almond Shortbread Crust & Crumb Topping

Arrange a rack in the middle of the oven and preheat to 350°F. Line an 8" square baking dish with parchment paper, leaving an overhang on all sides.

Place the flour, almond flour, brown sugar, almond extract and salt in a large bowl and stir to combine. 

Add the cold, cubed butter. Using a pastry blender or your fingers, cut the butter into the dry ingredients until butter hunks are the size of peas or smaller. The mixture should be crumbly and hold together when squeezed. Add 1/2 cup of the almonds, reserving remaining 1/4 cup for topping, and blend until just combined.

Set aside 1 cup of the crumble mixture for topping. Transfer the remaining mixture to the prepared baking dish and press it firmly and evenly into the pan to form the bottom crust. Parbake the crust for 10-12 minutes before topping, this will help keep the bottom crust from getting too soggy.

Blueberry Filling

Place the blueberries in a large bowl. Add the sugar, tapioca flour (or cornstarch), lemon zest and lemon juice and toss gently to combine. Allow the mix to sit for a few minutes before topping.

Assemble & Bake

Spread the blueberry filling in an even layer over the bottom crust. Sprinkle the reserved 1 cup of crumble mixture and remaining almonds over the blueberries.

Bake until the blueberry filling bubbling, the berries have started to collapse a bit and the topping is crisp and golden brown, about 40-45 minutes.

Allow to cool at least 2 hours in the pan. Then use the parchment paper to lift the baked slab from the pan. Using a sharp knife cut into a 4 x 4 grid to make 16 square bars and serve!