LEMON BARS ON BROWN BUTTER SHORTBREAD
1/2 confectioners' sugar, for crust
1 1/2 cups all-purpose flour, for crust
3/4 cup unsalted butter, at room temperature, for crust
1/2 cup pine nuts, for crust (optional)
1 cup plus 2 tablespoons lemon juice, for filling
Zest from one small lemon, for filling
6 large whole eggs, for filling
1 egg yolk, for filling
1/2 cup all-purpose flour, for filling
Pinch salt, for filling
2 1/4 cups sugar, for filling
Confectioners’ sugar for topping (optional)
Preheat the oven to 350º F. Butter a 9-by-13-inch baking pan.
To make the crust, sift the confectioners’ sugar into the bowl of a stand mixer fitted with the paddle attachment. Add the flour and stir to mix. Add the butter and pine nuts (if using) and beat on low speed just until a smooth dough forms.
Transfer the dough to the prepared pan and press evenly into the bottom and 1/2 inch up the sides of the pan. It should be about 1/4 inch thick. To help even out the crust, use the flat bottom of any type of cup, pressing down firmly.
Line the crust with parchment paper and fill with pie weights. Bake the crust until it colors evenly to a deep golden brown, 25 to 35 minutes. Rotate the pan 180 degrees if the crust appears to be baking unevenly.
While the crust is baking, make the filling: Sift the flour into a mixing bowl. Add the sugar and whisk until blended. Add the lemon juice and zest and stir to dissolve the sugar.
In a separate mixing bowl, whisk the whole eggs and egg yolk with the salt. Add the eggs to the lemon juice mixture and whisk until well mixed.
When the crust is ready, pull out the oven rack holding the crust and pour the filling directly into the hot pan. (It is easiest to pour the custard into the pan if the pan is in the oven.)
If the crust has come out of the oven and cooled before you have finished making the filling, put it back in for a few minutes so that it is hot when the custard is poured into it.
Reduce the oven temperature to 300ºF and bake just until the centre of the custard is no longer wobbly, 30 to 40 minutes.
Let cool completely on a wire rack, then cover and chill well before cutting. Using a sharp knife, cut into 12 squares, or as desired.
If you like, dust the tops of the squares with confectioners’ sugar. They will keep in an airtight container or well covered in the baking dish in the refrigerator for up to 4 days.