Preheat oven to 350F. Lightly coat an 8x4x2-inch loaf pan with cooking spray; set aside. In bowl combine eggs, onions, carrots, soy sauce, garlic, sesame seeds, lemongrass, ginger, and chili powder; add chicken. Mix well. Pat into pan.
Meanwhile, prepare noodles according to package directions; drain. Toss with 1/3 cup of the Pad Thai sauce. Return to pan; heat through. In a small saucepan heat remaining Pad Thai sauce and broth just to boiling. To serve, slice meat loaf; divide noodles among plates; top with meat loaf slices. Drizzle with Pad Thai-broth mixture. Sprinkle with onions and/or sesame seeds. Makes 8 servings.