01 - In a large bowl, combine ground beef, Italian seasoning, garlic powder, salt, and black pepper. Mix gently 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 until fully cooked through and nicely browned.
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, then place a cooked patty on top of each sauced bun.
05 - Spoon another tablespoon of pizza sauce over each patty, then layer with shredded mozzarella, pepperoni slices, sliced red onion, and sliced bell pepper.
06 - Place the baking sheet under the broiler for 1 to 2 minutes until the mozzarella is bubbly and fully melted. Watch closely to prevent burning.
07 - Remove from the oven, garnish with fresh basil leaves or red chili flakes if desired, and cap each with the remaining bun halves. Serve hot with extra pizza sauce on the side for dipping.