Preheat oven to 375 degrees. Place rack in the center of the oven.

Spray a 9 inch deep dish pie plate or an 8 x 8 x 2 inch baking dish with a non-stick cooking spray.

Put the flour, sugars, spices, butter, oats and nuts in a food processor and process until the mixture is crumbly. Make sure there are no large pieces of butter visible.

Set aside while you prepare the filling.

Place the apple chunks in a large bowl, along with the berries (if using) and lemon zest.

Toss with the lemon juice and sugar.

Transfer to the prepared baking dish.

Spread the topping evenly over the apples.

Bake for approximately 30-40 minutes, or until bubbly and the topping is golden brown.

Remove from oven and place on a wire rack to cool for about 30 minutes before serving.

Serve with softly whipped cream or vanilla ice cream.