Blackberry Crunch Bars - cooking recipe

Ingredients

Crust
3/4 cup unsalted butter (1 1/2 sticks, at room temperature and cut into chunks)
3/4 cup powdered sugar
2 cups all-purpose flour
1/4 teaspoon salt (reduce this to 1/8 tsp if you must use salted butter)
Filling
1/2 cup granulated sugar (plus 2 TB more if needed)
1 tablespoon cornstarch
1 pinch salt
4 cups fresh blackberries or 4 cups marionberries
1/2 lemon, zest of, grated
Topping
1/2 cup unsalted butter (1 stick, at room temperature and cut into chunks)
1 cup granulated sugar
1/2 teaspoon ground cinnamon
1/4 teaspoon salt (reduce this to 1/8 tsp if you must use salted butter)
1 cup all-purpose flour
1/4 teaspoon vanilla extract

Preparation

For the crust:
Preheat oven to 350. Lightly grease a 9x13 glass baking dish.
Place the butter, sugar, flour, and salt in the bowl of an electric mixer. On low speed with the paddle attachment, mix until the butter is in small pea-sized chunks. (This could also be done by hand with a pastry blender).
Press the mixture evenly into the bottom of the prepared baking dish. You can set aside the bowl to use for the topping.
Bake until the surface is dry and the edges are very lightly browned, about 20-22 minutes. Let cool at least 20 minutes before adding filling.
For the filling:
Pop a berry into your mouth. If it's an early-season berry from the store, it might be a little tart. If so, and you want make the filling a bit sweeter, add the extra 2 Tablespoons of sugar to the bowl in the next step.
In a mixing bowl, combine the 1/2 cup sugar (+ 2 T extra if needed), cornstarch, and salt. Stir in the berries and zest until combined. Set aside.
For the topping:
In the bowl of the electric mixer, place the butter, sugar, cinnamon, salt, flour and vanilla. On low speed with the paddle attachment, mix until the butter is in small pea-sized chunks and the mixture begins to clump together. (This could also be done by hand with a pastry blender).
To assemble:
Spread the filling on the cooled crust. Especially if the berries are large, the filling might not evenly cover the crust. That's OK.
Spread the topping over the filling. The whole thing will look pretty lumpy. That's OK.
Bake until the topping has browned lightly and the berry filling is bubbling, about 40 minutes.
Cool completely on a wire rack before cutting into bars. They are best eaten with a fork because they're a little crumbly.