Sift the sugar, lemon zest, and flour together in a large bowl.
Beat the eggs lightly to break up in a small bowl, then add to the dry mix, then the lemon juice until completely combined.
Pour filling over warm crust.
Bake the bars for 22-26 minutes or until the center is relatively set and no longer jiggles. (Give the pan a light tap with an oven mitt to test.)
Remove bars from the oven and cool completely at room temperature. I usually cool them for about 2 hours at room temperature, then stick in the refrigerator for 1-2 more hours until completely chilled.
Once cool, lift the parchment paper out of the pan using the overhang on the sides.
Dust with icing/confectioner’s sugar and cut into squares before serving. For neat squares, wipe the knife clean between each cut.
Cover and store leftover lemon bars in the refrigerator for up to 1 week or the freezer up to 4 months.