Preheat oven to 350 degrees.
Prepare a large baking sheet with parchment paper.
Heat olive oil over medium-high heat, add spinach and mushrooms, salt, pepper, onion powder, garlic powder. Cook until spinach has wilted a bit and mushrooms are tender.
Add black beans after drawing and rinsing them. Mix everything together. Cook for 5-7 minutes.
Lay out 5 tortillas on parchment paper. Carefully spoon filling on tortillas evenly.
Add shredded cheese on top of filling.
Add another tortilla on top of the filling. Press down gently with hand to make sure everything is in contact.
Bake in preheated oven for 10 minutes. When 10 minutes is up, gently and carefully flip the quesadillas over with large spatula. Cook for an additional 10 minutes, or until the tortilla shells are turning golden brown.
Let them cook off a bit until you slice into them.
Enjoy!