Summer is the time for desserts that celebrate all kinds of fruits, from melons, to stone fruits, to berries. Luckily, this slab pie from Claire Saffitz can be made all year round because it uses frozen blueberries. Wild are best (they’re smaller and sweeter, with a lower water content) but any blueberry will be delicious when given the pie treatment. Saffitz pairs them with warming spices—the traditional cinnamon plus ginger and cardamom, as well as blueberry’s best friend, lemon zest. The crust is all butter so make sure you give it time to adequately chill or else you’ll have a frustrating mess on your hands.
While this recipe can be made in our 13 × 9-inch Baking Dish, we especially love it in our Baking Slab, designed in partnership with Nancy Silverton (yes, you get not one but two baking legends with this recipe). If you’re into coordination, use the navy rimmed variation, but either way, it will be beautiful and delicious.
A fruit forward, summer dessert from our favorite dessert person.
For the pie dough, put 1½ cups of ice water in the fridge while you assemble the dough. In a large bowl or a food processor, combine the flour, granulated sugar, and salt, stirring or pulsing a few times to combine. Add the butter pieces and toss to coat in the flour mixture.
Break down the butter using your hands or long pulses of a food processor until butter is broken down into pieces no larger than a marble. If using a food processor, transfer mixture to a large bowl.
Measure out 1 cup of ice water and slowly drizzle it over the flour mixture, tossing constantly with a fork to distribute. Once all the water is added, switch to your hands and toss the mixture several times, then knead until big, shaggy pieces of dough form (there will still be unincorporated flour).
Transfer these shaggy pieces to the work surface, leaving the dry bits behind. Drizzle more ice water into the bowl 1 tablespoon at a time, mixing with a fork and then your hands after each addition, until all the dough comes together. It will still look floury and dry in many places but should hold together when squeezed.
Transfer dough to the work surface, divide in half, and press each half into a solid piece. Transfer each portion to a large sheet of plastic wrap and flatten into ¾"-thick squares. Wrap the dough tightly in the plastic, eliminating any air pockets. Use a Rolling Pin to flatten each portion into an even thickness. Transfer to the refrigerator. Chill both blocks of dough for at least 2 hours.
To shape the dough, let one block of dough sit at room temperature for a few minutes to soften slightly. Unwrap and place it on a lightly floured surface. Using a Rolling Pin, beat the dough across its surface to make it more pliable. Dust over top and bottom with more flour, then roll it out, adding more flour as needed, into a rectangular slab measuring about 15 × 10".
Use a wheel cutter or Chef Knife to cut the dough crosswise into strips measuring about 1" wide and 10" long. Place the strips on a parchment-lined baking sheet and refrigerate.
To make the filling, combine the blueberries, granulated sugar, cornstarch, lemon zest, lemon juice, vanilla, ginger, cinnamon, salt, and cardamom in a large bowl. Mix until combined and set aside.
Follow the same instructions as above for rolling out the second piece of dough, into a slightly thinner slab measuring about 16 × 12". Loosely fold the slab in half, then gently place onto Baking Slab (alternatively you can use our 13 × 9-inch Baking Dish) and unfold, leaving about ½" of overhang all the way around.
Press dough firmly into the bottom and against the sides. Brush the inside border of the overhang with some of the beaten egg, then scrape the blueberry filling into the crust and press firmly into an even layer.
Remove the strips of dough from the refrigerator and, starting at one end of the sheet pan, arrange them crosswise over the filling on a slight diagonal, overlapping the strips in a subtle zigzag. Press strips into the egg-washed border of the bottom crust and use scissors to trim off any excess.
Fold the overhang inward toward the filling along all four sides, then, using floured fingers to prevent sticking, crimp the border all the way around. Brush more egg around the border and over the strips, then generously sprinkle the top with demerara sugar. Chill or freeze the pie until the edge of the pastry is firm, 10–15 minutes. While dough is chilling, arrange an oven rack in the center position and preheat the oven to 425F.
To bake, place the Baking Slab or Dish on a foil-lined Sheet Pan and bake for 20 minutes. Reduce the oven temperature to 350F and continue to bake until top is deep golden brown and the filling is bubbling in the center of the pie, another 60–75 minutes.
Let the pie cool on a wire rack for at least 1 hour. Serve warm or room temperature slices drizzled with cold heavy cream. The pie will keep for up to 3 days, loosely covered and stored at room temperature, but the crust will soften over time.