Lightly grease a frying pan and place over a medium heat.
Spread 1 tablespoon of basil pesto over one of your tortillas and place it into your frying pan with the pesto side up. Add the baby spinach leaves, mozzarella cheese and feta.
Spread the last of the basil pesto over one side of the remaining tortilla and place it on top of the tortilla already in the pan.
Cook the Quesadilla for 3 minutes or until the tortilla begins to brown before carefully flipping over and cooking for another 3 - 4 minutes or until the cheese has melted and the tortilla has browned.