In a large bowl, mix the ground beef, Italian seasoning, garlic powder, salt, and pepper until well combined. Shape the mixture into 4 patties and set them aside.
Preheat a grill or grill pan and the broiler to medium-high heat. Place the buns, cut side up, on a baking sheet, and toast until golden. Remove the top halves and set them aside.
Grill the patties for 4-5 minutes on each side.
While the burgers are cooking, warm the pizza sauce in a small saucepan over low heat, stirring occasionally. Spread half of the sauce over the bottom buns and top with half of the mozzarella cheese and pepperoni. Broil for 2-3 minutes until the cheese is melted.
Place the cooked burger patties on the bottom halves of the buns and top them with the remaining sauce, cheese, and pepperoni. Broil until the cheese is melty, then place the top halves over the burgers.
