Fresh blueberries make these lemon bars a bit sweeter than usual, and very jammy, but without compromising their essential acidity. The grated lime zest gives the curd another note of citrus complexity. But if you’d rather leave out the lime, use more lemon zest. Or try playing with orange and grapefruit zests. The filling stays pretty soft in these tender bars, so it’s best to keep them in the fridge until right before serving, then dust with powdered sugar at the last minute.
- Serves: 16 persons
- 1 ¼cups/160 grams all-purpose flour
- ⅓cup/40 grams confectioners’ sugar, plus more for dusting
- 1teaspoon finely grated lemon zest
- ¼teaspoon fine sea salt
- 10tablespoons/140 grams cold unsalted butter, cubed
- 1 ½cups/300 grams granulated sugar
- ¾cup/180 milliliters fresh lemon juice (from 4 to 8 lemons)
- 3large egg yolks
- 2large eggs
- 2teaspoons cornstarch
- Pinch of fine sea salt
- 8tablespoons/113 grams unsalted butter (1 stick), diced
- ½tablespoon finely grated lemon zest
- 1 ½teaspoons finely grated lime zest (optional or substitute lemon zest)
- ¾cup/80 grams fresh blueberries
Step 1Heat oven to 325 degrees and line a 9-inch square baking dish with parchment paper so it hangs over the edges on all sides by a few inches. (You may need to use two pieces of parchment.)
Step 2Make the crust: In the bowl of a food processor, pulse to combine the flour, confectioners’ sugar, lemon zest and salt. Add butter and pulse until a crumbly dough forms, about 10 seconds. (Or mix dry ingredients in a bowl and use pastry cutter to cut in butter, clumping the mixture together in your hands until it holds together.) Press dough into prepared pan. Bake until light golden, 25 to 35 minutes.
Step 3As crust bakes, make the curd: In a medium pot, whisk together the granulated sugar, lemon juice, egg yolks, whole eggs, cornstarch and fine sea salt until well combined. Place over medium heat and stir with a heatproof rubber spatula (or wooden spoon), making sure to scrape around the sides and edges of the pot, until mixture is simmering and thickened, 5 to 10 minutes.
Step 4Bring mixture to a boil and let cook for about 30 seconds, but no longer than 1 minute. Immediately strain through a fine mesh sieve into a bowl. Stir in butter, lemon zest and lime zest, and stir until butter melts. Stir in blueberries.
Step 5Pour mixture over crust, then stir to evenly distribute berries. Return to oven, and bake until blueberries begin to burst and curd starts to turn golden around the edges, 33 to 45 minutes. Transfer to a wire rack to cool to room temperature. Chill in the refrigerator until thoroughly cold before cutting, at least 3 hours. Dust lightly with confectioners’ sugar right before serving.