Method

Prepare oven and dish

Preheat oven to 375°F (190°C). Lightly butter a 9-inch (23 cm) round or an 8x8-inch (20x20 cm) baking dish, or spray with nonstick cooking spray.

Make the fruit filling

Combine and macerate fruit

In a large mixing bowl, add the sliced apples (4 cups) and blackberries (2 cups). Sprinkle over 1 tablespoon granulated sugar, 2 tablespoons light brown sugar, 1 tablespoon lemon juice, and 1 teaspoon lemon zest. Toss gently to coat.

Add thickener and spices

Sprinkle 2 teaspoons cornstarch, 1 teaspoon ground cinnamon, and a pinch of salt over the fruit. Toss again until the fruit is evenly coated and the cornstarch is distributed. Let the mixture sit 10 minutes while preparing the topping so juices begin to release; this will make the filling saucier after baking.

Transfer to dish

Pour the fruit mixture into the prepared baking dish, spreading into an even layer and pressing down slightly to compact. Pour any accumulated juices from the bowl into the dish as well.

Make the crumble topping

Combine dry ingredients

In a medium bowl, whisk together 1 cup all-purpose flour, 3 tablespoons rolled oats, 1 tablespoon light brown sugar, 2 teaspoons granulated sugar, 1 teaspoon ground cinnamon, and a pinch of salt until evenly mixed.

Cut in butter

Add the 6 tablespoons cold, cubed unsalted butter to the dry mixture. Using a pastry cutter, two knives, or your fingertips, work the butter into the flour mixture until it resembles coarse crumbs with some pea-sized pieces of butter remaining (this gives flakiness).

Add nuts (optional)

Stir in 3 tablespoons cold chopped walnuts or pecans, if using, until evenly distributed through the crumble.

Top the fruit

Evenly scatter the crumble topping over the fruit layer in the baking dish, leaving some gaps so steam can escape and juices can bubble up. Gently press some larger crumbs onto the fruit so they crisp rather than sink.

Bake and finish

Bake

Place the dish on a baking sheet (to catch any drips) and bake in the preheated oven for 35–45 minutes, or until the topping is golden brown and the fruit filling is bubbling at the edges. If the topping browns too quickly, tent loosely with foil after 25 minutes and continue baking.

Rest

Remove the crumble from the oven and let it rest on a wire rack for 15–20 minutes. This helps the filling thicken as it cools and makes it easier to serve.

Serve

Scoop warm crumble into bowls and serve with vanilla ice cream or whipped cream if desired.

Apple And Blackberry Crumble Recipe