Lemon Meringue Pie Bars

Preheat the oven to 350 degrees (F). Line a 9-inch square metal baking dish with parchment paper leaving a 2-inch overhang on two sides. Spray the parchment paper and any exposed pan with nonstick baking spray. Set aside until needed.

In the bowl of a stand mixer fitted with the paddle attachment, beat the butter and sugar on medium-speed, scraping the bottom and sides as needed, until light and fluffy, about 3 minutes.

Add in the flour, cornstarch, and salt, and beat on medium-speed just until combined, scraping the bottom and sides of the bowl as needed. The mixture will be crumbly.

Press the mixture evenly into the bottom of the prepared baking pan. Bake for 25 minutes, or until golden brown and set. Transfer to a cooling rack to cool while you make the filling.

Reduce the oven temperature to 300 degrees (F).

In a large bowl combine the lemon zest and sugar and, using your hands, rub the lemon zest into the sugar until fragrant, about 2 minutes.

Add in the flour, cornstarch, salt, egg yolks, and eggs and whisk smoothly. Whisk in the lemon juice until evenly combined.

Pour the filling over the crust and return to the oven. Bake until the filling is just set, about 30 minutes. Transfer the pan to a wire cooling rack and cook completely. Then cover and chill for 1 hour. Or up to 48 hours.

Fill a large saucepan ⅓ of the way full with water. Bring to a simmer over moderate heat.

In a heatproof bowl that fits snugly on top of the pan, whisk together the egg whites, sugar, and salt.

Set the  bowl on top of the pan of boiling water and continue whisking until the mixture reaches 135 degrees (F) on a candy thermometer.

Carefully remove the bowl from heat. Using a handheld electric mixer, beat on medium-high speed until soft peaks have formed.

Increase the speed to high and continue beating until  stiff but spreadable peaks have formed.

Spread and swirl the meringue on top of the cooled lemon bars. Using a kitchen torch, brown the meringue. Slice and serve!