Preheat oven to 350°F.

Make crust: Put butter, flour, confectioner's sugar, 2 tsp lemon zest, and the salt in the bowl of an electric mixer fitted with the paddle attachment. Mix on medium speed until blended.

Transfer mixture to a 9 x 13-inch rimmed baking sheet. Press batter evenly into baking sheet. Bake 20-22 minutes till golden brown. Chill in freezer for 10 minutes. Let cool completely on a wire rack.

Make filling: Whisk together whole eggs, 1 3/4 cups plus 2 tablespoons granulated sugar, the lemon juice, and 1 tablespoon plus 2 teaspoons lemon zest. Pour over crust. Bake for 18 to 20 minutes making sure the filling is set. Let cool completely on a wire rack. Keep oven at 350°.

Make meringue topping: Put egg whites and 1/2 cup granulated sugar in the clean bowl of an electric mixer fitted with the whisk attachment. Beat on medium-high speed until stiff peaks form.

Using an offset spatula or the back of a spoon, spread meringue over filling, swirling to create soft peaks. Bake util meringue begins to brown, 8 to minutes. Let cool completely. Cut into bars. Bars can be refrigerated in an airtight container for up to 1 day.