Lemon Bars

Make the cookie crust

1. Spray a 9-inch (23-cm) square baking dish with nonstick cooking spray or generously butter it. Fold two 16-inch (40-cm) pieces of parchment paper or aluminum foil lengthwise to measure 9 inches wide. Fit 1 sheet in the bottom of the buttered dish, pushing it into the corners and up the sides of the dish (the overhang will help in removing the baked bars). Fit the second sheet of foil in the dish in the same manner, perpendicular to the first sheet. Spray the sheets with nonstick cooking spray or generously butter them.
2. In a small bowl, briefly process the flour, confectioners sugar, and salt to combine. Add the butter and process until blended, 8 to 10 seconds. Then process until the mixture is pale yellow and resembles coarse meal, about three 1-second pulses.
3. Sprinkle the mixture into the prepared dish and press it firmly with your fingers into an even layer over the entire bottom of the baking dish. Refrigerate for 30 minutes.
4. Preheat the oven to 350°F (175°C) and adjust an oven rack to the middle position. Bake the crust until golden brown, about 20 minutes. Place the pan on a wire rack while you make the lemon filling. Do not let the crust cool to room temperature.

Make the lemon filling

1. In a medium nonreactive bowl, whisk together the yolks and whole eggs until thoroughly combined but not frothy, 5 to 10 seconds. Add the granulated sugar and whisk until just combined, about 5 to 10 seconds. Add the lemon juice, zest, and salt and whisk until combined, 5 to 10 seconds.
2. Transfer the mixture to a medium nonreactive saucepan over medium-low heat, add the butter, and cook, stirring or whisking constantly, until the curd thickens considerably, 5 to 10 minutes.
3. Immediately pour the lemon mixture through a fine strainer set over a clean nonreactive bowl, pressing with the back of a spoon or spatula. Pour the heavy cream into the curd and stir until no streaks remain.

Assemble the lemon bars

1. Immediately pour the lemon filling onto the still warm cookie crust and bake until the filling is shiny and opaque and the filling in the center portion of the baking dish jiggles slightly when you shake the edge of the baking dish, 10 to 15 minutes.
2. Let the bars cool in the baking dish on a wire rack until room temperature, about 45 minutes. Remove the bars from the dish using the parchment or foil as handles and transfer everything to a cutting board. Cut the lemon bars into 2 1/2 inch squares, wiping the knife clean between cuts as necessary. Just before serving, dust some confectioners' sugar over the bars.