Layer 2 1/2 cups sliced apples in a greased 8-inch baking dish. Then, combine 1 cup flour, 1 cup sugar, 1/2 teaspoon cinnamon and 1/4 teaspoon salt. Cut in 1/2 cup of cold butter. Top apples with the flour mixture, and bake at 350 degrees Fahrenheit for about one hour.
To ensure a crispy crumble topping, avoid over mixing the butter. There should be visible lumps of butter in the flour before baking.
For more texture, rolled oats can also be added to the crumble topping. Chow's recipe for apple crumble calls for 2 1/2 pounds of granny smith and golden delicious apples. First, the apples are peeled, cored and sliced, then combined with 2 or 3 tablespoons of sugar, 3/4 teaspoon cinnamon and 1/8 teaspoon salt. The apples are then placed in a greased baking dish.
To make the topping, mix 1/2 cup brown sugar, 1/2 cup rolled oats, 1/3 cup flour and 1/8 teaspoon salt. Then, blend in half a stick of cold unsalted butter until the mixture is lumpy. Finally, cover the apples evenly in the crumble mixture, and bake in the oven for about one hour at 350 degrees Fahrenheit. If using apples that are particularly sweet, add less sugar to the apple mixture.