01 - In a large bowl, combine the ground beef, Italian seasoning, garlic powder, salt, and black pepper. Mix until evenly incorporated, then shape into 4 equal-sized patties.
02 - Heat olive oil in a skillet or grill pan over medium-high heat. Cook the patties for 4 to 5 minutes per side, or until fully cooked through and juices run clear.
03 - Preheat the oven broiler to high. Place the bottom halves of the burger buns on a baking sheet, cut side up.
04 - Spread 1 tbsp of pizza sauce onto each bun bottom. Place a cooked patty on top of each sauced bun.
05 - Spoon another tbsp of pizza sauce over each patty. Layer with shredded mozzarella cheese, pepperoni slices, thinly sliced red onion, and bell pepper strips.
06 - Place the assembled tray under the broiler for 1 to 2 minutes, watching carefully, until the cheese is bubbly and fully melted.
07 - Remove from the oven. Top with fresh basil leaves or red chili flakes if desired, then cap each with the remaining bun halves. Serve hot with extra pizza sauce on the side for dipping.