In the Lone Star State, thin and vinegary barbecue sauce is mopped onto meats as they smoke to keep them moist and flavorful. For ease, this recipe calls for prepared barbecue sauce, which gives it outstanding long-simmered flavor.
Whisk together barbecue sauce, apple cider vinegar, olive oil, chili powder, and garlic in a medium bowl; season with salt and pepper to taste. Cover and chill at least 30 minutes.
Dressing can be stored in an airtight container in refrigerator up to 5 days.