Preheat the oven to 375°F (190°C). Grease a 9-inch x 9 inch baking dish with cooking spray or oil.
In a large bowl, whisk together the dry ingredients: cornmeal, flour, baking powder, sugar, chili powder, garlic powder, onion powder, nutritional yeast (if using) and salt.
In a separate bowl mix together the wet ingredients: plant-based milk, vinegar, and oil.
Pour the wet ingredients into the dry ingredients and stir until just combined. Set aside.
In a large skillet, heat some oil over medium heat. Add the onion, jalapeno pepper(if using) and cook until softened (3 - 5 minutes), then add zucchini, bell pepper and garlic and sauté 1 - 2 minutes more.
Then add the black beans, tomatoes, corn, chili powder, cumin, smoked paprika, salt, and pepper to the skillet. Cook for another 5 minutes, stirring occasionally.
Pour the bean and vegetable mixture into the prepared baking dish. Spoon or pour the cornmeal batter evenly over the bean mixture. Gently spread it to the edges..
Bake for 30 to 35 minutes, or until the cornmeal topping is lightly golden and a toothpick inserted into the center comes out clean.
Let cool for a few minutes before serving.