1 cup (2 sticks) unsalted butter, chilled and cut into chunks
1 ¼ cups flour
¼ teaspoon salt
3-5 tablespoons ice water
4 whole eggs
4 egg yolks
2 cup sugar
2 cups flour
1 cup buttermilk, room temperature
1/2 cup (1 stick) unsalted butter, melted
2 teaspoons lemon juice
1 teaspoon lemon zest
1 teaspoon vanilla
½ teaspoon salt
Preheat oven to 350°F and arrange rack to lowest level. Line a 9×9-inch baking pan with aluminum foil and lightly grease with butter or nonstick spray.
In a food processor, combine flour, salt, and butter, and pulse until dough forms pea-sized chunks. Slowly add ice water in 1 tablespoon increments, pulsing until dough comes together.
Place dough in lined baking dish and press dough evenly out to sides.
For the filling, whisk dry ingredients (flour, sugar, and salt) together and stir until combined. Whisk in egg yolks, whole eggs, buttermilk, vanilla, lemon juice, and lemon zest, then slowly add melted butter and continue whisking until creamy.
Pour batter into baking dish. Place in oven and bake for 50-60 minutes, or until a golden crust forms at the top.
Remove and let cool on a wire rack.
Optional: Lightly dust with powdered sugar just before serving. Enjoy!