Preheat the broiler on your oven.
Place the poblano peppers on a gas stove or grill over medium-high heat. Cook, turning occasionally, until the skin is charred and blistered on all sides.
Transfer the peppers to a large bowl and cover with a lid or plastic wrap. Let sit for 10-15 minutes, until the peppers are cool enough to handle.
Using a sharp knife, carefully cut a slit down the center of each pepper and remove the seeds and membranes.
In a large bowl, combine the cooked quinoa, black beans, frozen corn, chopped cilantro, cumin, chili powder, smoked paprika, salt, and pepper. Use a fork to mix everything together.
Stuff each pepper with the quinoa and bean mixture, being careful not to overstuff.
In a separate bowl, whisk together the flour, cornmeal, baking powder, non-dairy milk, salt, and pepper until smooth.
Heat the vegetable oil in a skillet or griddle over medium-high heat.
Dip each stuffed pepper in the batter, making sure it is fully coated on all sides.
Place the battered peppers in the skillet or griddle and cook for 3-4 minutes on each side, until golden brown and crispy.
Transfer the cooked peppers to a baking sheet and bake in the oven for 10-12 minutes, until the filling is hot and the batter is fully cooked.
Serve hot and enjoy!