Ingredients:

  • 2 ½ cups All-Purpose Flour (Plain Flour), sifted
  • ¾ cup packed Light Brown Sugar
  • ¼ cup Granulated Sugar (Caster Sugar)
  • 1 tsp Ground Cinnamon (for crumb base)
  • ½ tsp Fine Sea Salt
  • 1 cup (2 sticks) Unsalted Butter, very cold, cut into ½ inch cubes
  • 1 Large Egg Yolk (optional)
  • 6 cups (approx. 5-6 medium) Cooking Apples (e.g., Granny Smith or Honeycrisp), peeled, cored, and diced
  • ¼ cup Granulated Sugar (for filling)
  • 2 Tbsp Cornflour (Cornstarch)
  • 1 Tbsp Lemon Juice
  • 1 tsp Ground Cinnamon (for filling)
  • ¼ tsp Ground Nutmeg
  • 1 tsp Vanilla Extract (optional)

Instructions:

  1. Prep and Preheat: Preheat the oven to 375°F (190°C). Line a 9x13 inch baking pan with parchment paper, ensuring a generous overhang to act as a sling.
  2. Combine Dry Ingredients: In a large bowl or food processor, combine the flour, brown sugar, granulated sugar, 1 tsp cinnamon, and salt for the crumb base.
  3. Cut in the Butter: Add the very cold, cubed butter and pulse briefly until the mixture resembles coarse sand and small pea-sized pieces of butter remain (do not over-mix).
  4. Reserve and Chill: Remove approximately 1 cup (120g) of the crumb mixture and set it aside in the fridge; this will be the streusel topping.
  5. Form the Base: If using the optional egg yolk, mix it briefly into the remaining crumb mixture. Transfer the mixture to the prepared baking pan. Press it down evenly and firmly across the bottom to form a solid base layer.
  6. Chill the Base: Place the pan with the pressed base layer into the fridge to chill for 30 minutes while preparing the filling.
  7. Prep the Apples: Peel, core, and dice the apples into uniform pieces (approx. 1/2 inch).
  8. Toss the Filling: In a separate medium bowl, toss the diced apples with the filling sugar, cornflour, lemon juice, 1 tsp cinnamon, nutmeg, and vanilla (if using). Ensure all apple pieces are coated.
  9. Assemble the Bars: Remove the chilled pan from the fridge. Spread the apple filling evenly over the shortbread crust.
  10. Top and Bake: Retrieve the reserved crumb mixture from the fridge and crumble it evenly over the apple layer. Bake for 40–45 minutes, or until the topping is golden brown and the apple filling is visibly bubbling thickly around the edges.
  11. Cool Completely (Crucial): Remove the pan from the oven and transfer it to a wire rack. Allow the bars to cool completely to room temperature—minimum 2 hours. The filling must set to allow for clean, structural bars.
  12. Cut and Serve: Once fully cool, use the parchment paper sling to lift the bars out of the pan. Place on a cutting board and slice into 12 equal bars.