Peel and cube sweet potatoes, boil in salted water until tender (8 minutes), drain and mash with 1 tablespoon olive oil; drain and warm black beans in a saucepan.
Juice the limes and blend with coconut cream and chopped cilantro to make crema; mince jalapeños and stir into mashed sweet potatoes with drained black beans.
Heat 2 tablespoons olive oil in a large skillet over medium-high heat, place a tortilla, spread one-quarter of sweet potato mixture on half, fold and cook until golden (2 minutes per side); repeat with remaining three tortillas and filling.
Cut each quesadilla in half and divide among four plates; drizzle with lime crema and serve.