Cut potatoes into 1-inch chunks. Place in a large saucepan, cover with water, then bring to a boil. Continue boiling until the potato chunks are fork-tender, about 8 minutes. Remove pot from heat, drain the potatoes, then return the potatoes to the pot and mash.
Stir in the chili powder, cinnamon, cumin, smoked paprika, 1/4 teaspoon kosher salt, and chipotle chili pepper until incorporated. Set aside.
Meanwhile, heat the olive oil in a large skillet. Add the onions and peppers and sauté until beginning to soften; about 3 minutes. Add the garlic and remaining 1/4 teaspoon salt. Continue to sauté until onions are translucent, about 5 minutes more.
Combine the sautéed vegetables with the sweet potato mash. Stir in black beans until all ingredients are evenly distributed.
Heat a large skillet over medium heat, then lightly coat with cooking spray. Place a single tortilla in a skillet, then spoon a heaping 1/2 cup of filling onto half of the tortilla and sprinkle with 3 tablespoons of shredded cheese. Fold the empty half of tortilla over the top.
Let cook until the bottom of the tortilla is browned and slightly crispy (about 1-2 minutes), then flip and brown the other side. Serve immediately with any desired toppings.
Notes
TO STORE: Leftover sweet potato black bean quesadilla filling can be refrigerated for up to 5 days. Whole assembled and cooked quesadillas may be stored in the fridge for up to 3 days.
TO REHEAT: Reheat filling in the microwave until heated through then assemble and cook as directed. Assembled quesadillas may be warmed in a skillet over medium-low heat until the filling is heated through and the tortilla is crisp.
TO FREEZE: Leftover filling may be kept in the freezer for up to 2 months. Defrost overnight in the fridge before using to assemble quesadillas.