Get ready: Preheat your oven to 350°F and prepare 2 large baking sheets by lining them with parchment paper or silicone mats.

Mix the filling: In a large bowl, combine the black beans, corn, bell pepper, cilantro, red onion, cumin, and a pinch of salt. Stir until everything is well mixed.

Assemble the quesadillas: Lay out the tortillas and on one half of each, sprinkle about 3 tablespoons of cheese. Top with 1/2 cup of the veggie mixture, then another 3 tablespoons of cheese. Fold the other half of the tortilla over to create a half-moon shape. Press down gently but firmly.

Bake to perfection: Place the quesadillas on the prepared baking sheets. Bake in the preheated oven for 20 minutes until the cheese is melted and the tortillas are slightly crispy.

Serve and enjoy: Let the quesadillas cool for 3-5 minutes. Then, cut each one in half using a serrated knife. Serve with your choice of salsa, guacamole, yogurt, or sour cream.