Preheat oven to 350°F and line an 8x8-inch pan with parchment paper.
Mix 1 cup flour, powdered sugar, butter, and salt until a dough forms, then press into the bottom of the prepared pan.
Bake crust 15-18 minutes until lightly golden.
Whisk eggs, granulated sugar, 2 tablespoons flour, lemon juice, and zest until smooth, then fold in blueberries.
Pour filling over hot crust and return to oven for 20-22 minutes until filling is set.
Cool completely, then refrigerate 1 hour before dusting with powdered sugar and cutting into bars.