Using a cheese grater or food processor, shred sweet potato.
Melt 1 T. Brummel & Brown spread in a frying pan.
Add shredded sweet potato and sliced onions and cook until potato is softened.
Put 1/4 of potato mixture on a flour tortilla, top with 1/4 cup spinach leaves, 1/4 cup mozzarella and another tortilla. (Repeat for each quesadilla.)
Melt a small amount of remaining spread in pan and fry quesadilla on both sides until lightly browned.
Optional: Top with salsa, avocado, and sour cream.