Preheat the oven to 375°F (190°C). Lightly oil a 9 x 13-inch (23 x 33 cm) baking dish.
Spread the chili evenly into the prepared baking dish.
Spoon the queso over the chili and spread into an even layer using an offset spatula or the backside of a spoon.
In a large mixing bowl, whisk together the cornmeal, masa harina, flour, baking powder, baking soda, salt, and egg replacer powder. Make a well in the center.
Add the maple syrup, plant milk, apple cider vinegar, and olive oil and mix with a rubber spatula until a smooth thick batter forms.
Fold in the shredded cheddar, hatch chiles, and corn kernels.
Spread the cornbread batter evenly over the chili and queso layers with a spatula.
Bake for 35 to 40 minutes, until the topping is golden brown and a toothpick inserted into the center comes out clean. Brush with vegan butter as soon as the casserole is removed from the oven. Let the tamale pie rest for 10 minutes before serving. Top each slice with a small dollop of sour cream, sliced scallions and cilantro.