Preheat your oven to 375°F (190°C).
Place the sliced apples in a 9x13 inch baking dish.
In a separate bowl, mix together the flour, rolled oats, brown sugar, cinnamon, nutmeg, vanilla extract, and salt.
Pour the melted vegan butter or coconut oil over the dry mixture and stir until well combined.
Spread the topping over the sliced apples in the baking dish.
Bake for 35-40 minutes, or until the topping is golden brown and the apples are tender.
Remove from the oven and let cool for a few minutes before serving.
Serve warm with vegan vanilla ice cream or whipped coconut cream, if desired.