These simple lemon bars have the most delicious buttery, crisp crust and creamy, tart lemon topping. Making the crust with melted butter rather than softened keeps it crisp and perfectly contrasted to the creamy, lemon filling on top. Don’t skip chilling the crust before baking, it really helps keep the crust crisp and crunchy. Lemons can vary when it comes to how sour they are. We like to taste our lemons to check for sourness. If they are really sour, we might consider adding a little extra sugar to the filling. Alternatively, if they are sweeter than usual, we’ll pull back the sugar amount (2 to 4 tablespoons should do it).
12 tablespoons (170 grams) unsalted butter, melted and cooled
1/2 cup (100 grams) granulated sugar
1 teaspoon lemon zest
1/2 teaspoon kosher salt
1 teaspoon vanilla extract
2 cups (260 grams) all-purpose flour
1 1/2 cups (300 grams) granulated sugar
3 tablespoons (25 grams) all-purpose flour
1/2 teaspoon kosher salt
2 teaspoons lemon zest
4 large eggs
3/4 cup (180 ml) freshly squeezed lemon juice (4 to 5 lemons)
1 to 2 tablespoons powdered sugar, for sifting tops of bars once cooled
Line a straight-sided 13 x 9-inch metal baking pan with foil, leaving an overhang on two opposite sides. (This will help when it comes to removing the cooled bars from the pan).
Lightly coat the sides of the foil, but not the bottom, with non-stick cooking spray or extra melted butter to prevent the lemon topping from sticking.
In a medium bowl, use a spatula to stir and press the sugar, salt, lemon zest, and the vanilla extract together until it looks moist and is fragrant. Stir in the flour and melted butter until a crumbly, stiff dough forms.
Press the dough evenly into the bottom of the prepared baking pan (it may not look like enough dough at first, but it will cover the bottom nicely). Prick the dough with a fork all over to prevent air bubbles while baking. Freeze dough for 5 minutes, or until firm (or refrigerate for 30 minutes).
Position an oven rack near the center of the oven and heat the oven to 325 degrees F. Bake the crust until lightly golden brown and set, 25 to 30 minutes.
While the crust bakes, stir the sugar, flour, salt and lemon zest together. Whisk in the eggs until smooth then whisk in the lemon juice.
Once the crust has baked, pour the lemon topping over the hot crust. Return the pan to the oven and increase the oven temperature to 350º F. Bake until the topping is set in the center and it no longer wiggles when the pan is moved, 20 to 25 minutes.
Set the pan on a cooling rack and cool until the bars are firm and the bottom of the pan is no longer warm, about 1 hour. (You can speed this up a little by placing the bars into the refrigerator once the pan is no longer hot).
Once cooled, use the overhang of foil to carefully lift the bars from the pan and place on a cutting board. Peel away the foil then cut into 16 bars or 32 small bars. Sift the powdered sugar over the bars.