For the Filling:

• 6 medium apples (mix of Honeycrisp and Granny Smith), peeled, cored, and sliced
• 1/3 cup brown sugar
• 1 tablespoon all-purpose flour
• 1 teaspoon cinnamon
• 1/4 teaspoon nutmeg
• 1 tablespoon lemon juice
• 1 teaspoon vanilla extract

For the Topping:

• 1 cup rolled oats
• 1/2 cup all-purpose flour
• 1/3 cup brown sugar
• 1/3 cup chopped pecans
• 1/2 teaspoon cinnamon
• Pinch of salt
• 6 tablespoons unsalted butter, melted

Instructions:

1. Preheat Oven: Preheat your oven to 350°F (175°C). Grease an 8×8-inch baking dish or similar size with butter or cooking spray.
2. Prepare the Filling: In a large bowl, combine the sliced apples, brown sugar, flour, cinnamon, nutmeg, lemon juice, and vanilla extract. Toss to coat the apples evenly. Transfer the apple mixture to the prepared baking dish.
3. Make the Topping: In a medium bowl, mix the oats, flour, brown sugar, pecans, cinnamon, and salt. Pour in the melted butter and stir until the mixture becomes crumbly.
4. Assemble: Evenly sprinkle the topping over the apples, covering them completely.
5. Bake: Place the dish in the preheated oven and bake for 35-40 minutes, or until the apples are tender and the topping is golden brown.
6. Serve: Let cool for about 10 minutes before serving warm. Pair with vanilla ice cream or whipped cream, if desired.