1. Heat 12-inch sauté pan over medium heat.
2. Spray tortilla with non-stick cooking spray. Place it flat on heated skillet for one minute then flip tortilla over.
3. Sprinkle one cup cheese on the tortilla, followed by half cup of each, corn and beans as well as four slices avocado.
4. Place another tortilla on top to make a sandwich. Cover pan with lid. After one minute, flip the quesadilla.
5. When cheese has melted, remove quesadilla and place on a warm plate; repeat with remaining tortillas, vegetables, and cheese.
6. Cut each quesadilla into four wedges. Top each piece with a dollop of salsa and sour cream before serving.