Preheat the oven to 180C/356F/Gas mark 4.
Mix together the lemon juice with the tapioca starch.
Place the persimmons in a large bowl.
Pour the tapioca/lemon juice mixture over the entire bowl of chopped persimmons.
Add the raw cane sugar, nutmeg, cinnamon and vanilla then proceed to coat the chopped persimmon.
Spread the persimmons evenly at the bottom of an oven proof 8x8 or 9x9 baking dish and set aside.
In another large bowl, add the ingredients to make the topping - jumbo oats, brown rice flour, raw cane sugar, cinnamon, and nutmeg then stir.
Add the vegan butter and rub the dry ingredients with the butter using your fingers and thumb to make a crumble texture.
Sprinkle the topping over the entire contents in the baking dish.
Bake in the oven for 30-35 minutes or until the top is golden brown.Allow to cool prior to serving.