Preheat your oven to 350°F (175°C) and lightly grease a 9x13 inch baking dish.
In prepared baking dish, combine the sliced apples, coconut sugar, lemon juice, vanilla extract, ground cinnamon, ground nutmeg, and cornstarch.
Mix until the apples are evenly coated. If you like a juicier filling, add ¼ cup of water or apple juice. Make sure the apples are spread out evenly.
In a separate bowl, whisk together the flour, sugar, baking powder, baking soda, and salt.
Add the cold vegan butter pieces to the flour mixture. Use a pastry cutter or your fingers to cut the butter into the flour until it resembles coarse crumbs.
In a small bowl, mix the non-dairy milk with the apple cider vinegar and let it sit for a minute to curdle slightly (this is your vegan buttermilk).
Pour the vegan buttermilk into the flour mixture and stir until just combined. Do not overmix.
Drop spoonfuls of the cobbler topping over the apple filling. It doesn’t need to be perfect - cobblers are meant to have a rustic look.
Bake in the preheated oven for 35-45 minutes, or until the topping is golden brown and the apples are tender and bubbling.
If the top is browning too quickly, cover it loosely with aluminum foil for the remainder of the baking time.
Let the cobbler cool for about 10-15 minutes before serving.