Ingredients
For the Shortbread Crust:
1/2 lb unsalted butter, (16 Tbsp) room temperature
1/2 cup granulated sugar
1 1/2 tsp vanilla extract
2 cups all-purpose flour
1/4 tsp salt
For the Lemon Filling:
7 large eggs, room temperature
3 cups granulated sugar, *
2 Tbsp lemon zest, from 4 to 5 lemons
1 cup lemon juice, freshly squeezed (from 5 large or 8 medium lemons)**
1 cup all-purpose flour
Confectioners sugar, to dust
Instructions
PREP: Preheat oven to 350˚F. Line a 13x9x2” baking pan with parchment paper (it should go most of the way up the sides so filling doesn’t spill over.
CRUST: In the bowl of a stand mixer fitted with the paddle attachment, cream together softened butter and 1/2 cup sugar. Add 1 1/2 tsp vanilla extract, 2 cups flour and 1/4 tsp salt. Continue mixing until mixture is crumbly and no dry flour remains. Spread the dough evenly into the bottom of your prepared pan. Press it with your fingertips to flatten and even out the dough. Bake crust at 350˚F for 18-20 minutes or until lightly golden at the edges. Transfer to a wire rack to cool slightly.
FILLING: While the crust is baking, zest then squeeze the lemons and prepare your filling. In a large mixing bowl, whisk together eggs and sugar until blended. Add Lemon juice and lemon zest and whisk to combine. Add 1 cup flour and whisk until smooth and very well blended and no traces of flour remain.
BAKING: Pour filling over the warm crust and bake in the center of a preheated oven at 350˚F for 30-35 minutes or until the filling is set. As soon as the filling is no longer wobbly in the center, remove from the oven so you don’t over-bake. Cool in the pan at room temperature for at least 1 hour then refrigerate for at least 2 hours before serving
TO SERVE: Pull the parchment paper up slightly to loosen from the pan then transfer to a cutting board and cut into 18-20 squares then dust the tops with powdered sugar