Preheat oven to 350 degrees.
Grease your loaf pan and set aside.
In a large mixing bowl, add ground beef, chopped onion, egg, rolled oats, 1 tsp garlic powder, 1 tsp salt, dried oregano, dried parsley, and seasoning salt.
Get two smaller bowls and split the tomato sauce evenly between the two bowl, setting one aside.
In one of the bowls of tomato sauce, add minced garlic, 1 tsp worcestershire, molasses, the remaining 1/4 tsp garlic powder, and onion powder. Mix well, then pour in with the meat and other ingredients.
Combine the meat and other ingredients really well. Use your hand to massage/knead it all together.
Split the ground beef mixture in half and place half in your loaf pan, flattening to cover the whole pan.
Cut some thin slices of cheese, just enough to cover the meat in the loaf pan.
Place the remaining meat in the loaf pan, covering the cheese, and shape it into a loaf.
Get the tomato sauce that you placed aside and add remaining 1 tsp worcestershire and 5 tsp bbq sauce(or A1), pour over the meat and spread to cover the meat.
Cover with foil, and bake for 2 hours. Place some tinfoil on a baking sheet and place on the rack under the meatloaf, to catch any spills.
After cooking for 2 hours, remove from oven, remove foil, add thin slices of cheese, then place back in over for 5 minutes more, just long enough to melt the cheese.