Preparation

Make the filling

• Put the strawberries, sugar, and lemon zest and juice in a medium heavy-duty saucepan, and stir to combine. Cook over low heat to dissolve the sugar, about 10 minutes. Use a potato masher to break up the strawberries a bit. Raise the heat to medium high, and bring to a boil. Reduce the heat and simmer, stirring often, until the mixture has thickened to jam consistency, 15 to 17 minutes. You should be able to drag a path through the bottom of the saucepan with a silicone spatula or wooden spoon. Scrape the jam into a heatproof bowl, and let cool completely. Remove and discard the lemon zest. (The jam can be stored in an airtight container in the refrigerator for up to 2 weeks.)

Assemble and bake the crostata

• Position a rack in the center of the oven, put a large rimmed baking sheet on the rack, and heat the oven to 350°F. Remove the pasta frolla from the refrigerator and let it rest at room temperature for 30 minutes to soften slightly. Have ready a 9-inch fluted tart pan with a removable bottom.
• Lightly dust a work surface and rolling pin with flour. Roll the larger disk of pasta frolla into a 12-inch circle, lifting and turning the dough as you roll to prevent sticking and create an even round. Gently wrap the dough around the rolling pin and unroll it over the tart pan. Gently fit the dough into the pan without stretching it. Use the palm of your hand or the rolling pin to trim off the excess. Refrigerate while you roll out the second piece of dough.
• Roll the smaller piece into a 10-inch circle and use a fluted pastry wheel to cut it into strips from 1/2 inch to 1 inch wide. (For a more traditional look, divide the disk into 10 pieces, and with your hands, roll each piece into a 10-inch rope.)
• Remove the crostata base from the refrigerator and spoon the jam into it, spreading it evenly. Position the strips of pastry on top of the jam in a crisscross lattice pattern. You can weave the strips if you like, but the dough is fragile and tends to
  tear so it’s not necessary (nor is it traditional). Press the edges of the strips into the edge of the tart shell to secure, and trim off the excess.
• Set the crostata on the heated baking sheet and bake until the crust is golden-brown, 25 to 30 minutes. Transfer from the
  baking sheet to a rack to cool completely. Remove the ring and use a large, wide-angled spatula to transfer the crostata from the
  metal tart base to a serving plate. Dust with confectioners’ sugar, if using, and serve.