Preheat oven to 350. Line baking sheet with foil and spray with cooking spray. Arrange potatoes and carrots on baking sheet; sprinkle with garlic powder and onion powder. Combine 1/2 cup cheese and mayonnaise in small bowl and mix well. Spread cheese mixture over vegetables. Spray another piece of foil with cooking spray and place on top; seal lightly around edges without pressing down on top. Bake 45 minutes. Remove top foil and continue baking until potatoes and carrots are tender and lightly browned on top. Sprinkle with remaining cheese and serve.