Preheat the oven to 375F. In a 9x13 casserole dish, add the sliced peaches, sugar, vanilla, lemon juice, and cornstarch and stir until coated.
In a separate bowl, add the cornmeal, flour, sugar, baking powder and salt, and stir. Add the coconut milk and apple cider vinegar, and stir until a thick dough is formed, adding additional coconut milk 1 tablespoon at a time if needed to thin.
Drop pieces of the dough onto the peach mixture, around 2 tablespoons at a time, about 1 inch apart. Flatten a bit with the back of a spoon.
Bake for 40 minutes, uncovered, until the peaches are bubbling and the dough is golden. Remove from the oven and allow to sit for 20 minutes before serving with vegan ice cream or whipped cream, as desired.