Bake sweet potatoes at 400 degrees for an hour. Cool.
Scoop pulp out of the sweet potatoes, place in a bowl. Add sour cream and seasonings. Mash to combine.
Spread a generous ½ cup of the mashed sweet potato on a tortilla. Top with 2 heaping tablespoons of black beans and about 2 tablespoons of cheese. Cover with another tortilla.
Grill quesadilla in a panini press, quesadilla maker, or a skillet until cheese is melted and tortilla is golden. Cut in wedges. Top with salsa and additional sour cream.
Recipe by Cooking with Veggies at https://cookingwithveggies.com/2013/09/16/sweet-potato-quesadillas/