In a blender, combine nut butter, lime juice, soy sauce, honey, ginger, scallion whites, garlic and 2 Tbsp. water; blend until smooth. Toss carrots with half of dressing. Add more dressing 1 Tbsp. at a time if desired. (Cover and refrigerate any leftover dressing for another use.) Gently toss in cilantro and scallion greens before serving.