In these pretty pink bars, the tartness of lemon is accentuated by freeze-dried strawberries, adding a dose of springtime flavor and a rosy hue.
Position a rack in the center of the oven and preheat to 350ºF. Line a 9-by-13-inch glass baking dish with foil leaving a 2-inch overhang on two sides. Grease the foil and dish with 1 tablespoon of the butter.
Combine the flour, butter, sugar cornstarch and salt in a food processor and pulse until the dough comes together, about 1 minute. Press the dough evenly into the bottom of the pan. Bake until the crust is golden at the edges, pale golden in the center, and firm, about 30 minutes. Transfer to a wire cooling rack.
Reduce the oven temperature to 300ºF.
Wipe out the food processor bowl and pulse the freeze-dried strawberries into a powder; reserve. Whisk together the eggs, egg yolks, sugar, and flour in a medium bowl until smooth. Whisk in the lemon juice, strawberry powder and melted butter.
Pour the filling over the warm crust and return to the oven. Bake until the filling is just set, 30 to 35 minutes.
Cool the lemon bars on a wire rack, 30 minutes. Use the foil to lift the bars from the pan and place on a baking sheet. Refrigerate until firm, at least 1 hour. Peel the foil off the bars, trim the edges and cut into 24 bars. Dust with confectioners’ sugar and serve.