In a large bowl, whisk together the 2 ½ cups all-purpose flour, 2 tbsp granulated sugar, and 1 tsp salt. Add the cubed 1 cup unsalted butter and use a pastry cutter or your fingers to blend it into the flour until the mixture resembles coarse crumbs.
2 ½ cups all-purpose flour, 2 tbsp granulated sugar, 1 tsp salt, 1 cup unsalted butter
Slowly add the ¼ cup ice-cold water, stirring until the dough just comes together. Divide the dough into two discs, wrap in plastic wrap, and chill for at least 30 minutes.
¼ cup ice-cold water
Preheat your oven to 375°F. Roll out one disc of dough on a floured surface to about ⅛-inch thickness. Cut into 3x4 inch rectangles to create the poptart bases and tops.
In a medium saucepan, whisk together the ½ cup fresh lemon juice, 1 tbsp lemon zest, ½ cup granulated sugar, and 3 large egg yolks over medium heat.
½ cup fresh lemon juice, 1 tbsp lemon zest, ½ cup granulated sugar, 3 large egg yolks
Cook, stirring constantly, until the mixture thickens, about 5-7 minutes. Remove from heat and whisk in the 4 tbsp unsalted butter until smooth.
4 tbsp unsalted butter
Transfer the lemon curd to a bowl and let it cool completely.
Place a tablespoon of cooled lemon curd in the center of each poptart base, leaving a small border around the edges.
Brush the edges with water, then place a matching dough rectangle on top. Use a fork to crimp the edges together and seal the poptarts.
Poke small holes in the top of each poptart to let steam escape. Bake for 20-25 minutes, until golden brown. Let them cool completely before adding the meringue.
In a large bowl, beat the 3 large egg whites with ¼ tsp cream of tartar on medium speed until soft peaks form. Gradually add the ½ cup granulated sugar, one tablespoon at a time, and continue beating until stiff peaks form. Add the 1 tsp vanilla extract and beat for another 30 seconds.
3 large egg whites, ½ cup granulated sugar, 1 tsp vanilla extract, ¼ tsp cream of tartar
Spread a generous layer of meringue on top of each cooled poptart.
Using a kitchen torch, lightly toast the meringue until golden and set. If you don’t have a torch, you can place the poptarts under the broiler for 1-2 minutes, watching closely to avoid burning.