1Spread 1 tablespoon of nut butter evenly over one side of 1 tortilla. Arrange strawberry and banana slices on top. Spread remaining nut butter on the other tortilla, and sandwich the tortillas together so the nut butter sides are touching. Press gently to help them stick together.
2Heat butter or oil in a large skillet over medium heat. When the butter is melted, add the quesadilla, flipping once, until golden brown, about 2 minutes per side.
3Allow to cool slightly and then cut the quesadilla into wedges. Serve with yogurt for a dipping sauce.