Preheat the oven to 425°F. Spray a large baking pan with cooking spray, set aside.
In a medium-size mixing bowl, mix together the beef, 1/2 bottle chili sauce, cheese, breadcrumbs, eggs, buttermilk, onion, Worcestershire sauce, BBQ seasoning, mustard, seasoned salt and garlic. Mix until the ingredients are fully combined.
Divide the mixture into 8 equal portions and form into oval loaves.
In a separate bowl, mix together the remaining chili sauce with brown sugar, vinegar, mustard and BBQ seasoning to make the glaze.
Spread 1/2 of the glaze onto the loaves before baking. (Reserved glaze to be used at the end of baking)
Bake for 23-25 minutes. Drizzle with the remaining glaze in the last 5 minutes of baking.
Rest for 5 minutes before serving.