- 4 large Golden Delicious apples (about 3 pounds)
- 1/4 cup sugar
- 1 lemon, juiced
- 2 tablespoons all-purpose flour
- 1/2 teaspoon ground cinnamon
- 1 cup walnuts or pecans, roughly chopped
- 1 cup all-purpose flour
- 1 1/4 cups rolled oats
- 1/2 cup packed dark brown sugar
- 1 teaspoon ground cinnamon
- Pinch fine salt
- 8 tablespoons (1 stick) cold butter, cut into small pieces
- Vanilla ice cream, for serving, optional
Position an oven rack in the center of the oven and preheat to 350 degrees F.
Peel, core, and slice apples into 1/4-inch slices. Place apples in a large mixing bowl and toss with sugar, lemon juice, flour, and cinnamon. Pour into a lightly greased 9 by 13-inch baking dish, and spread out into an even layer. Set aside.
In another large bowl, mix together the nuts, flour, oats, sugar, cinnamon, and salt for the topping. Using a pastry cutter or your fingers, gently work in the cold butter until pea-sized lumps are formed.
Top apples evenly with mixture and bake until apples are bubbly and topping is golden brown, about 45 minutes, rotating once halfway through cooking.
Serve warm or at room temperature with vanilla ice cream.