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 patties for 4 to 5 minutes per side 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 on each bun bottom. Place a cooked patty on top, then spoon another tbsp of pizza sauce over each patty.
05 - Layer shredded mozzarella, pepperoni slices, thinly sliced red onion, and bell pepper evenly over each sauced patty.
06 - Place the baking sheet under the broiler for 1 to 2 minutes until the mozzarella is bubbly and fully melted.
07 - Remove from the oven, garnish with fresh basil leaves or red chili flakes if desired, and cap with the top bun halves. Serve immediately with extra pizza sauce on the side.