Sunny Lemon Bars

Ingredients

• For the crust:
• 4 1/2 ounces all-purpose flour
• 2 ounces powdered sugar, preferably organic
• 1/4 teaspoon Diamond Crystal kosher salt; for table salt, use the same weight or half as much by volume
• 1/8 ounce freshly grated lemon zest
• 4 ounces cold unsalted butter, cut into 1/4-inch dice
• For the custard:
• 3 large eggs, cold
• 4 3/4 ounces egg yolks, from about 8 large eggs
• 9 1/2 ounces granulated sugar
• Pinch of kosher salt
• 1/4 ounce freshly grated lemon zest
• 11 ounces lemon juice, from about 8 large lemons
• For garnishing:
• 2 ounces powdered sugar, optional
• 6 ounces Lemon Chantilly, optional
• 5 ounces Crispy Citrus-Candied Pistachios, optional

Directions

1. For the crust, set an oven rack in the middle and heat the oven to 350 degrees F. Fit parchment into an anodized-aluminum baking pan measuring 8- by 8- by 2-inch, using a sheet long enough to hang over the sides. In the food processor bowl, pulse the butter, flour, powdered sugar, salt, and lemon zest until the mixture looks dry and gravelly, about 12 1-second pulses. Tip it into the lined pan, pat it out evenly, and bake until the crust is lightly golden and set, about 30 minutes. Use it while hot, or cover it well and leave it at room temperature until you need it, up to 48 hours.
2. For the custard, put the whole eggs and yolks into a 3-quart stainless steel saucepan, add the sugar, salt, and lemon zest, and whisk in the lemon juice. Set the pan over low heat and cook, stirring steadily and gently, until the mixture feels warm, about 3 minutes. Raise the heat to medium-low; keep stirring as it cooks until the custard is thick and steaming, and an instant-read thermometer should show 170 degrees F, about 8 minutes. Strain it right away into the crust, spread the top level, and cover the pan with aluminum foil. Bake until the filling is even and set, about 10 minutes. Take off the foil and let the bars cool to room temperature, then cover again and chill until cold and firm, about 1 hour.
3. To serve, slide a bench knife or butter knife around the pan to release the chilled custard. Grab the parchment overhang, ease the slab free, and lift it onto a cutting board. Slice into 16 2-inch squares, washing the knife after each cut. Serve them plain, with a light powdered sugar shower, or with Lemon Chantilly and Crispy Citrus-Candied Pistachios on top. For storage, use an airtight container for up to 1 week.