Ingredients:

  • 2 ¼ cups All-Purpose Flour (Base/Topping)
  • 1 ½ cups Rolled Oats (Old-Fashioned) (Base/Topping)
  • 1 cup Light Brown Sugar, packed (Base/Topping)
  • ½ cup Granulated White Sugar (Base/Topping)
  • 1 ½ teaspoons Ground Cinnamon (Base/Topping)
  • ¼ teaspoon Ground Nutmeg (Base/Topping)
  • ½ teaspoon Salt (Base/Topping)
  • 1 cup Unsalted Butter, very cold, cubed (Base/Topping)
  • 6 cups Firm Baking Apples, peeled, cored, and diced (Filling)
  • ¼ cup Granulated White Sugar (Filling)
  • 1 tablespoon fresh Lemon Juice (Filling)
  • 2 tablespoons All-Purpose Flour (Filling)
  • 1 teaspoon Ground Cinnamon (Filling)
  • Pinch of Salt (Filling)

Instructions:

  1. Preheat oven to 375°F (190°C). Line a 9x13 inch (23x33 cm) baking pan with parchment paper, ensuring there is an overhang on the long sides to create a sling.
  2. In a large bowl, whisk together all dry ingredients for the crumble (flour, oats, both sugars, cinnamon, nutmeg, salt).
  3. Cut in the cold, cubed butter until the mixture resembles coarse, pea-sized crumbs. Reserve approximately 1 ½ cups of this mixture for the topping.
  4. Press the remaining crumble mixture firmly and evenly into the bottom of the prepared pan to create the base layer.
  5. In a separate bowl, toss the diced apples with sugar, lemon juice, flour, cinnamon, and salt until everything is evenly coated.
  6. Spread the apple filling evenly over the prepared base layer.
  7. Scatter the reserved crumble mixture evenly over the apples. Do not press the topping down.
  8. Bake for 45–50 minutes, or until the topping is golden brown and the apple filling is bubbling thickly around the edges.
  9. Remove from the oven and let the bars cool completely on a wire rack. This cooling period (minimum 2 hours) is crucial for clean slicing.
  10. Once completely cool, use the parchment sling to lift the entire block out of the pan and slice into 16 squares.