Ingredients
The crumble topping:
3/4 cup granulated sugar
3/4 cup all-purpose flour
3/4 teaspoonground cinnamon
1 teaspoon kosher salt
8 tablespoons (1 stick) cold unsalted butter, cut into pieces + more for greasing the baking dish
The fruit filling:
4 pounds apples, peeled, cored and sliced
1 vanilla bean
Juice of 1 lemon
1/2 cup brown sugar
2 tablespoons all-purpose flour
1/2 teaspoon ground cinnamon
Preparation
To make the crumble topping, mix the sugar, flour, cinnamon and salt together in a bowl. Work the butter in with your hands until incorporated and the mixture looks crumbly. Set aside or refrigerate until ready to use. Preheat the oven to 375°. Butter the bottom and sides of 3 1/2-quart gratin dish or 9- by 13-inch glass baking dish. Place the apple slices in a bowl. Split the vanilla bean, and scrape the seeds into a small bowl with the lemon juice, breaking the seeds up with your fingers. Discard the vanilla bean pod. Add the lemon juice/vanilla mixture to the apples, along with the brown sugar, flour and cinnamon; toss with your hands to combine. Spread the apple mixture into the prepared baking dish; sprinkle the topping evenly over the apples. Bake until the crumble topping hardens and turns golden brown and the apples are softened, about 60-70 minutes.
