Place the shrimp in a medium bowl and add the lime juice, 1 tablespoon olive oil, chile powder, garlic powder, salt, pepper and onion powder. Mix well and place in the refrigerator for 5 minutes.
In a medium sauce pan heat the olive oil over medium-high heat. Add the shrimp. Cook about 5 minutes or until they are cooked.
On a work surface, spread 2 of the tortillas. Sprinkle the cheese over the bottom of each tortilla. Add the shrimp evenly on top of the cheese, sprinkle with scallions, then top with cilantro. Top with another tortilla.
Heat a large nonstick skillet with cooking spray over medium heat. Carefully place 1 quesadilla in pan and cook 2 minutes.
Using a spatula, gently flip the quesadilla and cook an additional 2 minutes until lightly browned and cheese is melted. Repeat with second quesadilla.
Serve warm with salsa.