In small bowl, combine all dressing ingredients except milk; beat with wire whisk until smooth. Stir in milk. Set aside.
Heat oven to 400°F. Spray cut surfaces of muffin halves with nonstick cooking spray. Sprinkle with garlic powder. Cut into 1/2-inch pieces; place on ungreased cookie sheet. Bake at 400°F. for 8 to 10 minutes or until crisp.
Meanwhile, in large salad bowl, combine all salad ingredients. Add dressing; toss until well coated. Arrange salad on 4 individual salad plates. Top with croutons.