Preheat your oven to 400 F.
Add 1 TBSP olive oil to a skillet over medium heat. Then add the sweet potatoes and onions with a little salt and pepper. Cover the pan and let the potatoes and onions cook down for about 10-15 minutes, until the sweet potatoes are pretty soft.
Add the green bell pepper, black beans, garlic, chili powder, paprika, cumin and more salt and pepper. Stir well and cook until the bell pepper has softened, about 10 more minutes.
Assemble the quesadillas: Spray a baking sheet with cooking spray. Add a tortilla and sprinkle 1/2 cup of cheese over one half. Scoop about 3/4 cup of filling on top of the cheese. Sprinkle another 1/2 cup cheese on top of the filling. Fold the tortilla over so it covers the filling and press down gently to even it out. Repeat 2 more times. Note that if you have extra filling, you can freeze it on its own or make more quesadillas to freeze in the future!
Bake the quesadillas at 400 F for 15-20 minutes. No flipping needed! Let them cool before cutting and placing in containers.