Brown butter elevates lemon bars
Deep thinkers debate good versus evil, while baked goods, which have goodness baked right in, debate good versus better, which is to say butter versus brown butter.
Butter set over steady heat separates; left to sizzle, the milk solids toast in the milk fat, turning sweet, creamy butter into rich, nutty brown butter.
If brown butter is better than butter, imagine how good a baked good is when baked with better butter. Really, really good.
Brown-Butter Lemon Squares
Prep: 75 minutes plus overnight chill
Bake: 10 minutes
Makes: 24 squares
Butter for pan
3 cups sugar
Finely grated zest of 4 lemons
11/2 sticks (12 tablespoons) unsalted butter, in chunks
2 teaspoons vanilla extract
1/2 teaspoon baking soda
1/2 teaspoon kosher salt plus a pinch
1 cup plus 7 tablespoons plus 2 tablespoons flour
1 cup plus 3 tablespoons freshly squeezed lemon juice (from 6 big or 12 small lemons)
Prep: Lightly butter a 13-by-9-inch glass baking pan. Line with parchment paper, leaving some overhang. Set rack in lower third of oven.
Buzz: Measure sugar into the food processor. Scatter in zest. Buzz, 30 seconds. Scoop out 1/3 cup scented sugar; cover tightly and set aside (for gilding top). Measure 6 tablespoons scented sugar into a large mixing bowl (for brown-butter pastry). Dump remaining scented sugar into a large saucepan (for lemon curd).
Brown: To make pastry, drop butter into a medium saucepan. Set over medium heat. Butter will melt, foam and begin to bubble. Let bubble, scraping bottom of pan with a soft spatula, until butter is dotted with brown specks, about 8 minutes. Scrape butter and specks over the 6 tablespoons sugar in the mixing bowl. Stir in vanilla, baking soda and 1/2 teaspoon salt. Stir in 1 cup flour. Knead in 7 tablespoons flour; pastry will be stiff. Pat into prepared pan (bottom only, not sides).
Brown: Bake at 325 degrees until pastry browns, 28-30 minutes. Cool on a rack at least 15 minutes.
Whisk: Meanwhile, make the curd. Whisk remaining 2 tablespoons flour and the pinch of salt into the sugar in the large saucepan. Whisk in juice and eggs. Set over medium heat and whisk thick, 6-8 minutes. Press through a fine-mesh strainer.
Bake: Smooth lemon curd over cooled pastry. Bake at 300 degrees until set, 10-12 minutes. Cool completely. Press plastic wrap against lemon surface. Cover pan. Chill overnight.
Serve: Uncover. Grasp parchment overhang and lift lemon block out of pan. Sprinkle surface with reserved scented sugar and spread with an offset spatula. Use a long, heavy knife to trim edges. Cut into 24 squares.