• Preheat the oven to 350℉. Line a 13x9-inch baking pan with foil, extending the foil over the edges of the pan. Spray the foil with nonstick spray.

PREPARE THE CRUST:

• In a large bowl, whisk together the flour, powdered sugar, cornstarch and salt. Use a pastry blender to cut in the butter until the mixture resembles coarse crumbs. Press into the bottom of the prepared pan. Bake for 18 to 20 minutes or until the edges are light brown.

PREPARE THE FILLING:

• In a medium bowl, whisk together the eggs, sugar, flour, lemon zest, lemon juice and half/half or cream. Pour the filling over the hot crust. Sprinkle the blueberries on top. Bake for 20 to 25 minutes, until the center is set. Cool completely in the pan on a wire rack. Use the edges of the foil to lift the uncut bars out of the pan. Place on a cutting board; cut into bars. Just before serving, sift powdered sugar over the tops of the bars. Cover and store in the refrigerator for up to 3 days.