Preheat oven to 350F. Oil a pie dish (or any similar size pan) and set aside.
Mix all filling ingredients in a mixing bowl. Transfer to the pie dish and spread evenly.
Mix all topping ingredients (except sliced almonds reserved for garnish, if using) in a separate small mixing bowl until coarse crumbs form. Sprinkle this mixture over the apples in the pie dish. Garnish with sliced almonds if desired.
Bake in a preheated oven for approx 30 minutes, until the crumble turns golden brown.
Remove from oven and serve immediately (with a side of vegan vanilla ice-cream, non-dairy yogurt, or whipped cream -- highly recommended) or chill if you like your apple crumble cold (makes a great gluten-free vegan breakfast!). Enjoy!