To make the cobbler topping, place the cornmeal, oats, flour, salt, and baking powder in a large bowl. (I use the same bowl I just used for the apples. No need to wash.) In a small bowl, stir together the egg, coconut oil, maple syrup, and coconut milk. Pour this mixture into the oat mixture, and stir to combine well. The mixture should stick together easily, so add another tablespoon or two of milk if it seems too dry. Transfer the cobbler topping mixture to the slow cooker and spread it evenly on top of the apples.