Preheat your oven to 350°F (175°C). Grease a 7x11-inch baking pan and set aside.
In a mixing bowl, combine the flour and sugar for the crust and topping. Add the cold, cubed butter and use a pastry cutter or fingers to work the butter into the dry ingredients until the mixture resembles coarse crumbs.
1 cup all-purpose flour
Press about two-thirds of this crumb mixture evenly into the bottom of the prepared pan to form the crust. Bake for 15 minutes until lightly golden.
Meanwhile, prepare the fruit filling by combining chopped strawberries, lemon juice, sugar, and cornstarch in a bowl. Mix gently until the strawberries are coated and the mixture is slightly thickened.
1 cup all-purpose flour
Pour the strawberry-lemon filling over the baked crust, spreading it evenly with a spatula. Then sprinkle the remaining crumb mixture over the top, covering the filling completely.
Bake the assembled bars for an additional 25-30 minutes, or until the topping is golden brown and the filling is bubbling around the edges.
Allow the bars to cool in the pan for at least 20 minutes. This helps the filling set and makes slicing easier.
Slice into squares and serve slightly warm or at room temperature, enjoying the bright, crisp-crumble contrast.
