Preheat the oven to 375°F (190°C).

In a skillet, heat olive oil over medium heat and sauté diced green bell peppers and onions for about 5 minutes.

In a mixing bowl, combine ground beef, breadcrumbs, egg, milk, Worcestershire sauce, garlic powder, salt, and black pepper. Mix gently.

Press half of the meat mixture into a greased loaf pan to create the base.

Layer four slices of provolone cheese over the meat mixture in the loaf pan, then add the sautéed bell peppers and onions on top.

Cover the cheese and vegetables with the remaining meat mixture, pressing down firmly.

Bake for 45-50 minutes until the internal temperature reaches 160°F (71°C). Add remaining provolone cheese for the last 5 minutes of baking.

Let the meatloaf rest for 5-10 minutes before slicing. Optionally, garnish with fresh parsley.