In a large bowl, mix together oats, flour, brown sugar, salt, cinnamon, and cold butter cubes with your hands to create a crumbly topping. Set aside.
Make the filling
In a large bowl, mix together the apples, cranberries, flour, brown sugar, vanilla, orange juice, cinnamon, nutmeg until well combined.
Add filling mixture to a 10- to 12-inch cast iron skillet (or other oven-safe skillet) and spread out evenly.
Top with the topping and bake at 350°F for about 35-45 minutes, until the the top is golden brown and the crisp is slightly bubbling.
Cool on a cooling rack for 10-15 minutes before serving.
Notes
Makes approximately 8 servings.Storage: While this is best enjoyed immediately, leftovers will keep in an airtight container in the refrigerator for up to one week.Make ahead: