01 - In a large bowl, combine the ground beef, Italian seasoning, garlic powder, salt, and black pepper. Mix gently until evenly incorporated, then divide and shape into 4 equal-sized patties.
02 - Heat olive oil in a skillet or grill pan over medium-high heat. Sear the patties for 4 to 5 minutes per side, or until fully cooked through and juices run clear.
03 - While the patties cook, preheat the oven broiler to high. Arrange the bottom halves of the burger buns on a baking sheet.
04 - Spread 1 tablespoon of pizza sauce onto each bun bottom, then place a cooked patty on top.
05 - Spoon another tablespoon of pizza sauce over each patty. Layer with shredded mozzarella, pepperoni slices, thinly sliced red onion, and bell pepper strips.
06 - Place the baking sheet under the broiler for 1 to 2 minutes, until the mozzarella is bubbling and fully melted.
07 - Remove from the oven. Garnish with fresh basil leaves or red chili flakes if desired, cap with the top bun halves, and serve immediately with extra pizza sauce on the side.