• Preheat oven to 350°F
• Lightly butter a 10" cast iron skillet or a 9" x 13" baking dish
• Peel and core apples and then cut into ¼" cubes. Set aside.
• Lightly toast oats and pecans in a dry pan and set aside to cool

FILLING:

• Make the filling:

  In a large bowl add the filling ingredients: Brown sugar, flour, cinnamon, nutmeg, salt, and vanilla. Blend well.
• Add cubed apples to the filling mix and blend gently until mixture is coated.
• Spread apples and filling evenly into the prepared cast iron or baking dish, set aside.

TOPPING:

• Make the topping:

  Whisk together the flour, brown sugar, and cinnamon in a medium bowl. Cut in ½ cup cold unsalted butter (retain ¼ cup for later) using a fork or pastry cutter.

  Blend until the mixture becomes super crumbly.
• Fold toasted oats and pecans into the topping mixture and mix lightly. Sprinkle evenly over apple mixture.
• Bake for 40-45 minutes or until topping is bubbling around the edges.

  Remove from the oven and increase the oven temperature to 425°F.
• Using a cheese grater, shred the remaining ¼ cup cold unsalted butter evenly over the topping. Return to oven.
• Bake for an additional 10 minutes at 425°F. Remove from the oven.

  Let cool for about 15-20 minutes and serve warm.