Serves 6 to 8.
Position a rack in the lower third of the oven. Preheat the oven to 350 degrees F. Liberally butter the baking dish.
To make the topping: Combine all of the ingredients and mix well. Set aside.
To make the filling: in a medium saucepan, combine the orange zest, juice, and chopped apricots, and bring to a simmer, and cook until the apricots are soft. Set aside.
In a large bowl, mix the sugar and cinnamon. Halve and core the apples. Lay each half cut side down and cut twice in each directly to make 9 chunks. Add the chunks to the bowl and toss apples with the sugar and cinnamon. Stir in the apricots and juice from the saucepan.
Scrape the mixture into the buttered baking dish and spread evenly. Distribute the crumbly topping evenly over the apples. Bake until the crisp is browned on top and the juices are bubbling and thickened, about 1 1/4 to 1 1/2 hours. Serve warm, cool or cold, with or without very lightly sweetened whipped cream.