Heat oil in a large skillet over medium heat until hot. Add onion and garlic; cook and stir 2 to 3 minutes, or until tender.
Stir in peanut butter, sweet potatoes and beans; mash slightly. Add cumin, cinnamon and cayenne pepper; mix well. Reduce heat to low, cover and simmer 2 to 3 minutes or until thoroughly heated. Stir.
Meanwhile, heat tortillas according to package directions. To serve, spoon and spread 1/2 cup sweet-potato mixture across center third of each tortilla. Top with salsa, sour cream, green onions and cilantro. Spread to cover sweet potato mixture.
Fold sides of each tortilla 1 inch over filling. Fold bottom 1/3 tortilla over filling; roll again to enclose filling. Place seam side down on platter. Makes 6 burritos.