Coat a large nonstick skillet with cooking spray; place over medium-high heat until hot. Add onion; cook, stirring constantly, 5 minutes or until tender. Remove from skillet. Wipe skillet with a paper towel.
Coat skillet with cooking spray; place over medium heat until hot. Place one tortilla in skillet. Cook 1 minute or until bottom of tortilla is golden. Sprinkle one-fourth onion, cheese, and cumin over one side of tortilla. Fold tortilla in half. Cook tortilla 1 minute on each side or until golden and cheese melts. Repeat procedure with remaining tortillas, onion, cheese, and cumin.
Top each quesadilla with 2 tablespoons salsa and 2 tablespoons sour cream. Serve immediately.
Cooking Light Low-Fat, Low-Calorie Quick and Easy Cookbook
