01 - In a large bowl, combine ground beef, Italian seasoning, garlic powder, salt, and black pepper. Mix gently until just combined, then form 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 until fully cooked through.
03 - While the patties cook, set your oven broiler to high. Arrange the burger bun bottoms on a baking sheet.
04 - Spread 1 tbsp of pizza sauce on each bun bottom. Place a cooked patty on top, then spoon another tablespoon of pizza sauce over each patty.
05 - Layer shredded mozzarella, pepperoni slices, thinly sliced red onion, and bell pepper evenly over each patty.
06 - Place the baking sheet under the broiler for 1 to 2 minutes until the cheese is bubbly and fully melted.
07 - Remove from the oven, add fresh basil leaves or red chili flakes if desired, and top with the remaining bun halves. Serve hot with extra pizza sauce for dipping.