6 to 8 medium Granny Smith apples (peeled, cored, and sliced)
1/2 cup granulated sugar
1 tablespoon ground cinnamon
1 tablespoon lemon juice
1 cup old-fashioned rolled oats
1 cup all-purpose flour
1 cup packed light brown sugar
1/2 cup unsalted butter (cold and cubed)
1/2 teaspoon ground nutmeg
1/4 teaspoon salt
Instructions
Preheat your oven to 375°F (190°C). Lightly grease a 9×13 inch baking dish or a large oval casserole dish with butter or non-stick cooking spray to prevent the fruit juices from sticking.
In a large mixing bowl, combine the sliced apples, granulated sugar, lemon juice, and half of the cinnamon. Toss the ingredients together until the apples are evenly coated. Pour the apple mixture into the prepared baking dish and spread them out in an even layer.
In another bowl, combine the rolled oats, flour, brown sugar, remaining cinnamon, nutmeg, and salt. Use a pastry cutter or your clean fingers to work the cold, cubed butter into the dry ingredients. Continue until the mixture looks like coarse crumbs and the butter is roughly the size of small peas.
Evenly sprinkle the oat crumble mixture over the top of the apples in the baking dish. Do not press the topping down; leave it loose so it stays light and crunchy during the baking process.
Place the dish in the preheated oven and bake for 40 to 45 minutes. The topping should be golden brown and the apple juices should be bubbling around the edges. Remove from the oven and let it cool for at least 10 minutes before serving to allow the juices to thicken.