- 3 large Granny Smith apples, peeled and sliced
- 3/4 cup white sugar
- 2 tablespoons ground cinnamon
- 1 teaspoon ground nutmeg
- 2 tablespoons lemon juice
- 1/4 cup butter, softened
- 3/4 cup white sugar
- 1 egg
- 2 cups all-purpose flour
- 2 teaspoons baking powder
- 1/4 teaspoon salt
- 1/2 cup milk
- 2 cups fresh blueberries
- 2/3 cup white sugar
- 1/2 cup all-purpose flour
- 1 teaspoon ground cinnamon
- 1/3 cup cold butter
- Place apples in a large bowl and toss with 3/4 cup sugar, 2 tablespoons cinnamon, nutmeg, and lemon juice. Cover the bowl and place in refrigerator.
- Preheat oven to 375 degrees F (190 degrees C). Grease a 9×13-inch baking dish.
- Beat softened butter and 3/4 cup white sugar together in a large bowl until creamy; beat in egg.
- Mix 2 cups flour, baking powder, and salt together in a small bowl. Stir flour mixture into butter mixture, alternating with milk, until fully incorporated. Fold in blueberries.
- Arrange apples in a single layer in the bottom of the prepared baking dish. Pour blueberry batter over apples.
- Mix 2/3 cup sugar, 1/2 cup flour, and 1 teaspoon cinnamon together in a bowl; cut in cold butter until mixture is crumbly. Sprinkle crumb topping over batter.
- Bake in the preheated oven until a toothpick inserted in the center of the buckle comes out clean, 40 to 45 minutes. Cool on a wire rack.