1) Preheat the oven to 180 degrees C/Gas 4. Butter a 23 by 35 by 5-cm oval baking dish.
2) Peel, core, and cut the apples into large wedges. Combine the apples with the zests, juices, sugar, and spices. Pour into the dish.
3) To make the topping, combine the flour, sugars, salt, oatmeal, and cold butter in the bowl of an electric mixer fitted with the paddle attachment. Mix on low speed until the mixture is crumbly and the butter is the size of peas. Scatter evenly over the apples.
4) Place the crisp on a sheet pan and bake for 1 hr until the top is brown and the apples are bubbly. Serve warm.