1. Adjust oven rack to middle position and heat oven to 350 degrees. Whisk oil and garlic in large bowl; reserve 1/4 cup. Toss bread with remaining oil mixture and season with salt and pepper. Bake bread on rimmed baking sheet until golden, about 20 minutes. Cool completely.
2. Process mayonnaise, grated Parmesan, anchovy (if using), lemon juice, vinegar, Worcestershire, mustard, 1/2 teaspoon salt, and 1/2 teaspoon pepper in blender until smooth. With machine running, pour in reserved oil and process until thoroughly incorporated.
3. Toss romaine, shredded Parmesan, and dressing in large bowl. Add croutons and toss to combine. Season with salt and pepper. Serve.