Name: Sumac Blueberry & Cherry Slab Pie
Ingredients: 1 Tbsp apple cider vinegar or distilled white vinegar; ½ cup (114g) water; 2 ½ cups (300g) all-purpose flour; 1 Tbsp granulated sugar; 1 tsp kosher salt; 1 cup (226g) unsalted butter, cold and cubed; ⅓ cup (66g) granulated sugar; 1 Tbsp Spicewalla Sumac; 2 cups (340g) fresh blueberries; 1 cup (160g) fresh cherries, stemmed, pitted, and halved [1]; ¼ cup (28g) tapioca starch; pinch of kosher salt; 1 large egg; splash of cream; turbinado, demerara, or other coarse sugar

Instructions

Start by preparing the pie dough. Mix vinegar and water together, then add a few ice cubes. Store in fridge until ready to use.
In a large bowl, whisk together flour, sugar, and salt.
Add cold, cubed butter, tossing around gently to coat. Using a pastry blender or fork, cut in butter until the pieces of butter are roughly pea sized. (You’ll want to have some that are a little bigger and some that are a little smaller to maximize the delicious flakiness!)
Add ice cold water one tablespoon at a time, quickly mixing together with your hands. Continue adding water one tablespoon at a time until the dough comes together. The goal is for the dough to hold together when squeezed into a ball, but with a few dry bits still left in the bowl.
NOTE: Do NOT add all of the water at once. You don’t want the dough to get so wet that it becomes sticky.
Divide dough in half. Wrap each half in cling film, then press into a patty shape. Place wrapped dough in fridge overnight. (You could refrigerate for only two hours if you’re in a hurry, but overnight is recommended.)
After your dough has chilled, make the filling. Combine sugar and sumac in a small bowl. Using your fingers, rub together to infuse the sugar with the sumac.
Place blueberries and halved cherries in a medium bowl. Sprinkle sumac-infused sugar, tapioca starch, and salt on top, then mix well. Let sit for at least 15 minutes.
Flour your work surface and rolling pin. Retrieve one dough patty from fridge, place on your well-floured surface, and sprinkle top with a little bit of flour.
Begin gently rolling out the dough into roughly a 11" x 15" rectangle, making sure to pick up and rotate the dough every few rolls.
Gently place dough into a quarter sheet pan. (We used this one.) Delicately, yet firmly press dough into bottom and up sides of pan. Trim edges of dough so they’re even with edges of pan.
Spoon filling into pan, spreading out evenly. Place pan in fridge.
Retrieve other dough patty from fridge. Roll out until it’s ¼-inch thick. Using a cookie cutter or paring knife, cut decorative shapes out of pie dough.
Get your pie from the fridge and place dough cut-outs however you like over the filling.
Place pie back in fridge and let chill for 1 hour.
Towards the end of the chilling time, heat oven to 350°F.
Whisk egg together with a splash of cream. Brush onto crust cut-outs. Sprinkle with turbinado, demerara, or other coarse sugar.
Bake for 60–70 minutes until crust is golden and the filling is bubbling.
Transfer to wire rack to cool for at least an hour before serving. This allows the filling to set a bit more.
Enjoy with homemade whipped cream or ice cream!

Sumac Blueberry & Cherry Slab Pie