Preheat the oven to 350˚F.
In a large mixing bowl, combine diced apples with maple syrup, brown sugar, apple cider, lemon juice, cornstarch, pumpkin pie spice (or the substitute), and salt. Stir well to coat the apples evenly.
Transfer the apple filling mixture to a 9 or 10" cast iron skillet or baking dish. Bake uncovered for 30 minutes.
In another large mixing bowl, combine all the topping ingredients. Stir well to combine.
After 30 minutes, remove the apples from the oven, stir, and evenly top with the crumble mixture.
Return to the oven and bake for an additional 25-30 minutes until the crumble is lightly browned and crispy.
Remove from the oven and let it cool for a few minutes. Serve hot with vegan vanilla ice cream.