I add mayonnaise and sour cream to a bowl. Then I whisk them until smooth and creamy. This creates the rich base you want.

I pour in the buttermilk and white vinegar. I whisk again until everything blends well and looks silky.

Now I add garlic powder, salt, and black pepper. I mix gently so the seasoning spreads evenly.

I gently fold in the blue cheese crumbles. I keep some chunks for texture because that is what makes it taste restaurant-style.

I cover the bowl and refrigerate the dressing for at least 30 minutes. This helps the flavors come together beautifully.