In a medium bowl, smash together 2 1/2 ounces blue cheese and buttermilk until it is the consistency of large curd cottage cheese.
Add sour cream, mayonnaise, vinegar, sugar, and garlic powder. Mix until well combined. Season with salt and pepper to taste. Let dressing set for 5 minutes to let flavors marry.
Place lettuce on a plate “pointy” side up. Drizzle with dressing. Top with crumbled blue cheese and bacon. Die and go to heaven.