Preheat your oven to 350°F (175°C). Lightly grease a 9x9-inch baking dish or line it with parchment paper for easy removal.
Prepare the crust: In a medium bowl, mix the flour, sugar, and salt. Add the cold, cubed butter and use a pastry cutter or fork to cut it into the flour mixture until it resembles coarse crumbs. Gradually add ice water, 1 tablespoon at a time, until the dough begins to come together. Press the dough evenly into the bottom of the prepared baking dish.
Bake the crust for 15-18 minutes, or until it’s lightly golden. Remove from the oven and let it cool while you prepare the filling.
Prepare the filling: In a large bowl, whisk together the eggs, sugar, flour, cornstarch, and salt. Stir in the lemon juice and lemon zest until well combined. Gently fold in the blueberries.
Pour the filling over the cooled crust and bake for an additional 25-30 minutes, or until the center is set and lightly golden.
Allow the pie bars to cool completely in the pan. Once cooled, refrigerate for at least 2 hours before cutting into bars.
Optional: Dust the bars with powdered sugar before serving for an extra touch of sweetness.