Crumble topping (Makes about 3 cups crumbs)
3/4 cup unbleached all-purpose flour
1/2 cup sugar
1/2 teaspoon salt
1/4 pound (1 stick) cold unsalted butter, cut into 3/4-inch pieces

Prepare the Filling
Position a rack in the middle of the oven. Preheat the oven to 350°F. Put the apples in a glass or ceramic baking container with a 2 1/2-quart capacity. Either an 8- or 9-inch square baking dish or a 9 1/2- to 10-inch diameter round pie dish, both with 1 3/4- to 2-inch high sides, works well. Mix the sugar and cinnamon together in a small bowl. Sprinkle the sugar mixture and lemon juice over the apples. Stir the mixture to combine the ingredients, spreading them in an even layer in the baking dish. Set aside.

Mix the Topping
Put the flour, sugar, and salt in a large bowl and use a large spoon to stir them together. Add the butter pieces, stirring to coat them with the flour. Rub the butter pieces and flour between your thumb and fingertips or cut them together with a pastry blender until coarse crumbs form that are about 1/2 to 3/4 inch in size, there is no loose flour, and the mixture looks pale yellow rather than white. Spread the crumbs evenly over the apple mixture.