This post is originally dated November 2007 (!!). Recently updated with a few recipe tweaks and a new photo.
After being in league with a bountiful table of meat and more meat, vegetables glistening with butter and seven types of starchy carbohydrates, holiday desserts should probably be an exercise in balance. Then again, holidays like these are really the only time that one can legitimately have dessert with their dessert. But something lighter, cleansing, after the first dessert course. A "side dessert", if you will. Pumpkin pie is a must in most circles, but even the most delicious wedge topped with a bulb of whipped cream can seem one-dimensional after consuming so many different flavors during the main part of the meal. Since I volunteered for dessert duty this holiday season, I opted to serve my pumpkin pie with a side of lemon bar.
Lemon bars are one of those great all-American desserts that one can find a mind-boggling amount of recipes for with a single Google search. But nearly every recipe starts with a simple, parbaked shortbread crust that is covered with a lemon curd mixture and baked until set. And please don't forget the snowy blanket of confectioners' sugar.
I've been using the lemon bar recipe from Williams-Sonoma's Dessert cookbook ever since receiving it as a wedding gift five years ago with fine results, but there were a few things about those bars that I always wanted to tweak. Since the lemon curd layer went into the oven as a an uncooked liquid, the crust lost its snap by the time the bars were baked and completely set. And no matter how gently I whisked the aforementioned lemony liquid, there were always a series of unsightly bubbles that appeared on the surface of the baked curd. Sure, I could cover it with confectioners' sugar, but it just wasn't as pretty. And good lemon bars are all about the pretty--delicate, a bright, taut surface, fresh and sweet-tart. This Thanksgiving's lemon bars deserved better.
I found a recipe that looked promising in my trusty Baking Illustrated. Although it was a bit more time consuming than the recipe I had been using, I was prepared for it. America's Test Kitchen always promises us the best results, but rarely the fastest way to get there. Anyway, this recipe calls for a cooked curd to be poured onto the baked crust, which allows for a much shorter final baking time and less time for the curd to make the crust soggy in the oven. And when set, the cooled lemon filling is much shinier, smoother and more sturdy than the Williams-Sonoma recipe. Hooray!
Just between us, I discovered a little trick for giving even better flavor to lemon bars. Normally, I like to use Meyer lemons in lemon desserts for their sweeter, almost floral quality. But since I shopped for groceries the day before Thanksgiving and the zoo that was the grocery store didn't have Meyer lemons and I was not about to make a special trip to a store across town in search of them, I replaced a bit of the lemon juice with freshly squeezed orange juice. This small tweak gave the curd the hint of sweetness and slightly golden color that Meyer lemons would have given this recipe, without the time spent in traffic to get them and the additional expense. This just might have to become a permanent tweak.
Adapted from Baking Illustrated
Serves 12 to 16
For the crust:
1 1/4 cups/160 g unbleached all-purpose flour
1/2 cup/60 g confectioners' sugar, plus more for dusting
1/2 teaspoon fine sea salt
8 tablespoons/113 g unsalted butter, softened but still cool, cut into 1-inch pieces
For the filling:
7 large egg yolks
2 large whole eggs
1 cup plus two tablespoons/212 g granulated sugar
1/2 cup/113 g freshly squeezed lemon juice
3 tablespoons freshly squeezed orange juice
Finely grated lemon zest of 2 large lemons (about 1/4 cup)
1/8 teaspoon fine sea salt
4 tablespoons/57 g unsalted butter, cut into 4 pieces
3 tablespoons heavy cream
Position a rack to the center of the oven and preheat it to 350 degrees F. Grease an 8-inch square baking pan with nonstick cooking spray and line it with two 9-inch wide strips of parchment paper or heavy duty aluminum foil, placed perpendicular in the pan and nestled into the corners and up the sides of the pan to create parchment "handles" that will make the bars easy to remove from the pan later. Grease the parchment as well.
In a food processor or by kneading with your fingertips, combine the flour, confectioners' sugar, salt and butter pieces until the mixture is pale yellow and resembles coarse meal. Sprinkle the crust mixture into the prepared pan and press it firmly and evenly over the bottom of the pan. Refrigerate for 30 minutes. Bake the chilled crust for about 20 minutes, or until it is golden brown.
While the crust is baking, prepare the filling: Whisk together the yolks, whole eggs until combined, then slowly rain in the sugar, whisking until just combined. Whisk in the lemon and orange juices, lemon zest and salt until well-blended. Pour the mixture into a medium saucepan over medium-low heat, add the butter pieces and cook the curd, stirring constantly with a wooden spoon. When the curd reaches 170 degrees on a candy or instant-read thermometer (it will have thickened to a sauce consistency).
Immediately pour the curd through a fine-mesh sieve over a medium bowl, encouraging it through by stirring slowly with your wooden spoon. When all the curd is strained, stir in the heavy cream and immediately pour the curd into the warm crust. Bake the lemon bars at 350 degrees for 10 to 15 minutes, until the filling is shiny, opaque, and only jiggles slightly in the center few inches of the pan. Cool on a wire rack to room temperature, about one hour. Remove the bars from the pan using the parchment "handles" and cut into 12 or 16 bars using a large chef's knife, wiping the blade between cuts for perfectly clean edges. Generously dust the bars with confectioners' sugar just before serving. Store leftovers in an airtight container in the refrigerator for 3 to 4 days.