Lemon Meringue Bars with Shortbread Crust

Instructions:

1. Preheat oven to 350°F (175°C). Line a 9x9 inch baking pan with parchment paper, leaving an overhang on the sides.
2. Pulse flour, sugar, and salt in a food processor (or use a pastry cutter) with cold butter until the mixture resembles coarse crumbs.
3. Press the dough firmly and evenly into the bottom of the pan.
4. Bake for 15–18 minutes until the edges are just barely golden. Remove from the oven and set aside.
5. In a saucepan, whisk together sugar, cornstarch, and flour to remove lumps.
6. Stir in lemon juice and zest over medium heat until the mixture begins to thicken and bubble.
7. Remove from heat and slowly whisk in the eggs one at a time to prevent scrambling.
8. Pour the lemon mixture over the warm crust and spread evenly.
9. In a clean bowl, beat egg whites, cream of tartar, and salt on medium speed until soft peaks form.
10. Gradually add sugar one tablespoon at a time, increasing speed to high and beating until stiff, glossy peaks form.
11. Spread the meringue over the lemon filling, sealing the edges against the crust.
12. Bake until the meringue peaks are golden brown.
13. Allow to cool completely and chill in the refrigerator for 3 hours before slicing into 16 squares.