Preheat the oven to 400 degrees F. Cook the 2/3 cup frozen corn according to package directions. While the corn is cooking, thinly slice the poblano pepper crosswise starting from the bottom end, and finely chop any remaining portion near the stem.
In a large skillet over medium heat, add the cooked corn, 2 tsp. avocado oil, and pasilla peppers. Stir and cook for 2 minutes, then add the ½ tsp. garlic powder, ¼ tsp. kosher salt, ¼ tsp. pepper, ½ tsp. cumin, ½ tsp. dried oregano, ¼ tsp. smoked paprika, and ¼ tsp. chili powder. Stir and cook another 3 to 4 minutes.
Place the 2 flatbreads on a baking tray next to each other. Spread 1 cup (total) of the vegan cheddar and vegan mozzarella evenly across the flatbreads, leaving a bit of crust open around the edge. Then, evenly spread the poblano and corn mixture across the flatbreads. Then spread the remaining ½ cup cheese across the flatbreads. Sprinkle the flatbreads with a dash of salt and pepper.
Place the flatbreads into the oven to bake for 8 to 10 minutes, or until the flatbreads are crisp. While the flatbreads are in the oven, finely chop the 2 tbsp. cilantro and add all the Spicy Mayo ingredients to a small bowl (2 tbsp. vegan mayo, 1 tsp. agave nectar, 2 to 3 tsp. hot sauce, and juice of ¼ lime. Stir the mayo thoroughly.
To serve, top the flatbreads evenly with the chopped fresh cilantro, the 2 tbsp. hot sauce, and drizzle with the Spicy Mayo as desired.