Ingredients:

  • 3 ½ cups All-Purpose Flour (Chilled)
  • 2 Tbsp Granulated Sugar
  • 1 tsp Kosher Salt
  • 1 ½ cups Unsalted Butter (Cold, Cubed)
  • ½ cup to ¾ cup Ice Water
  • 8 large Granny Smith Apples (Peeled, Cored, Sliced ¼ inch)
  • ½ cup Light Brown Sugar (Packed)
  • ¼ cup Granulated Sugar
  • 3 Tbsp Cornstarch
  • 2 tsp Ground Cinnamon
  • ½ tsp Ground Nutmeg
  • 1 Tbsp Lemon Juice
  • 1 cup All-Purpose Flour (For topping)
  • ¾ cup Old-Fashioned Rolled Oats (For topping)
  • ¾ cup Light Brown Sugar (Packed, For topping)
  • ½ tsp Kosher Salt (For topping)
  • 8 Tbsp Unsalted Butter (Melted, For topping)

Instructions:

  1. Combine the flour, sugar, and salt for the crust in a large bowl or food processor. Cut in the cold butter using a pastry blender or by pulsing until the mixture resembles coarse meal with pea-sized pieces.
  2. Gradually add ice water, mixing only until the dough barely comes together. Do not overmix. Divide the dough in half, form into flat disks, wrap tightly, and chill for at least 90 minutes.
  3. In a large bowl, gently toss the sliced apples with the filling sugars, cornstarch, cinnamon, nutmeg, and lemon juice. Set aside.
  4. Create the crumb topping: Combine the topping flour, oats, brown sugar, and salt. Pour in the cooled melted butter and mix with a fork until large, moist clumps form. Set aside.
  5. Preheat your oven to 375°F (190°C). Lightly grease an 18x13 inch half sheet pan.
  6. On a floured surface, roll one disk of dough into a large rectangle (about 20x15 inches). Carefully transfer the dough to the sheet pan, pressing it into the corners. Trim the excess, leaving a 1-inch overhang.
  7. Pour the prepared apple mixture evenly over the crust base. Sprinkle the Oat Crumb Topping evenly over the apples.
  8. Fold the 1-inch dough overhang up and over the filling edges, crimping as needed to form a raised rim.
  9. Bake for 50 to 60 minutes, or until the topping is deep golden brown and the apple filling is bubbling thickly in the center.
  10. Allow the Ultimate Sheet Pan Apple Slab Pie to cool completely on a wire rack for a minimum of 3 hours before slicing to allow the filling to set properly.