Creamy Lemon Squares
with Brown Butter Crust
Photo: Laura Murray
These lemon bars borrow some magic from key lime pie. Sweetened condensed milk is thickened with lemon juice and yolks, instead of cooking a traditional curd on the stovetop. With the power of a posset and baked custard combined, this simple filling is supple and delicate. There’s plenty of lemon juice and zest (I really want to make you pucker), so the nutty brown butter crust keeps things grounded. If you’ve saved a vanilla pod after scraping the seeds for meringue or steeping in cream, add it to the butter while it browns to extract even more of its floral aroma.
Excerpted from "Start Here: Instructions for Becoming a Better Cook" © 2023 by Sohla El-Waylly with permission of Alfred A. Knopf, a division of Penguin Random House LLC. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Ingredients
For the Crust
- 113 grams (1 stick) unsalted butter, cut into pieces
- spent vanilla pod (optional)
- 60 grams (1/2 cup) powdered sugar
- ¼ teaspoon Diamond Crystal kosher salt
- 1 large egg yolk (about 20 grams)
- 120 grams (1 cup) all-purpose flour
Ingredients
For the Filling
- 5 large egg yolks (about 100 grams)
- one 14-ounce can sweetened condensed milk
- 2 teaspoons finely grated lemon zest
- scant ¼ teaspoon citric acid (optional)
- pinch kosher salt
- 150 grams (2/3 cup) freshly squeezed lemon juice (from 4 to 5 lemons)
- powdered sugar, for dusting
Method
1. Make the crust: In a medium saucepan over medium heat, melt butter and spent vanilla pod (if using) until foamy, about 3 minutes. Continue cooking butter, stirring and scraping frequently with a stiff silicone spatula, until the sputtering has subsided, and the butter solids look deeply browned, 3 to 5 minutes
2. Remove from heat, scrape the butter and any brown bits at the bottom into a large bowl. Set aside until cool, slightly solid, but still creamy, about 20 minutes in the refrigerator or 2 hours at room temperature.
3. Heat the oven to 325F. Grease an 8-inch metal brownie pan and line the bottom and two sides with one long sheet of parchment, leaving an inch of overhang.
4. Pluck out the vanilla pod (if you used one), scraping any butter still clinging to it (rinse and reserve for another use). Using a stiff silicone spatula, stir the sugar and salt into the butter. Add the egg yolk and stir until evenly combined. Add the flour and stir until the mixture comes together into a crumbs. Use your hands to press the crumbs together into a dough.
5. Dump the dough into the prepared pan. Use your hands and an offset spatula to spread the dough into an even layer. Prick all over with a fork and bake until dry and lightly golden, about 30 minutes. Cool fully, at least 30 minutes. (Tightly wrapped, crust will keep at room temperature for 5 days.)
6. Increase the oven to 350F.
7. Make the filling: In a large bowl, whisk the egg yolks, condensed milk, zest, citric acid (if using), and salt until well combined. Add the lemon juice and whisk until evenly incorporated. Pour over the cooled crust.
8. Bake until the center is just set, about 14 to 16 minutes. Transfer to a rack to cool 1 hour, then place in the fridge to chill fully, at least 2 hours and up to overnight.
9. Run an offset spatula or butter knife along the edges of the pan to loosen the bars. Use the parchment to lift them onto a cutting board. Using a sharp knife and wiping clean in between slices, cut into 16 squares. Dust with powdered sugar and serve. (Tightly wrapped, store leftovers in the fridge for 5 days.)
NOTE: You can double this recipe and bake in a 9 by 13-inch pan. Increase the bake time for the custard by 5 minutes.
Yield
Makes 16 squares