Preheat oven to 450 degrees F. Spray cookie sheet with cooking spray. In large bowl, toss sweet potatoes, green onions, and salt and pepper. With 1/4 measuring cup, scoop packed sweet potatoes onto pan to form 12 mounds, 2 inches apart. Flatten slightly. Spray tops with cooking spray. Bake 25 minutes or until browned at edges. In large bowl, whisk mayonnaise, lime juice, and soy sauce. When cakes are cooked, add baby kale, black beans, and edamame to dressing. Toss until coated. Serve cakes over salad.