Lemon Bars

Steps

1. Preheat oven to 350°F. Line a 9×9-inch baking pan with parchment paper, leaving overhang on two opposite sides for lifting out the bars later.
2. In a medium bowl, beat 1 cup softened butter, ½ cup granulated sugar, and ¼ teaspoon salt with an electric mixer until pale and fluffy, about 2 minutes. Add 1½ cups of the flour and mix on low until a crumbly dough forms and holds together when pressed.
3. Press the dough evenly into the bottom of the prepared pan. Prick the surface all over with a fork, then bake until the edges are lightly golden and the center is set, 18 to 22 minutes.
4. While the crust bakes, whisk together the 1½ cups granulated sugar and remaining ½ cup flour for the filling in a large bowl. Whisk in the 4 eggs one at a time until smooth, then whisk in the lemon juice, lemon zest, and baking powder until fully incorporated and free of lumps.
5. Pour the filling over the hot crust immediately after it comes out of the oven. Reduce the oven temperature to 325°F and return the pan to the oven.
6. Bake until the filling is set around the edges and the center jiggles only slightly when the pan is nudged, 18 to 22 minutes. The surface should no longer look wet.
7. Let the bars cool completely in the pan on a wire rack, about 1½ to 2 hours, then transfer to the refrigerator and chill for at least 2 hours until thoroughly cold and firm.
8. Use the parchment overhang to lift the block out of the pan onto a cutting board. Sift powdered sugar evenly over the top, then slice into 16 squares with a sharp knife, wiping the blade clean between cuts.