Preheat oven to 400°F. Line a large, rimmed baking sheet with foil and mist with cooking spray. Spread bread out on sheet and mist with cooking spray. Turn and mist opposite side. Sprinkle with garlic seasoning and 1/4 tsp pepper. Toss well and spread in a single layer. Bake until lightly toasted, turning halfway, about 10 minutes.
Meanwhile, prepare dressing: To a blender, add anchovies, yogurt, onion, buttermilk, mustard, oil and Worcestershire sauce and blend on medium-high speed until smooth.
Add lettuce to a large bowl. Add about three-quarters of dressing and toss well to combine. Add additional dressing if desired. (NOTE: It's best to start with less dressing or you'll end up with a soggy salad.) Add cheese and toss again. Divide evenly among plates and top evenly with croutons. Grind additional pepper over top.
Serving Size: 1 1/2 cups salad and 1/4 of croutons