In a small bowl, combine 4 tablespoons of softened unsalted butter with 2 cloves of minced garlic and 1 tablespoon of finely chopped fresh parsley. Mix until well blended. Set aside.

Slice your hamburger buns in half and spread the prepared garlic butter generously on the cut sides. Heat a skillet over medium heat and toast the buns buttery side down for 2-3 minutes until golden brown.

In a mixing bowl, combine the lean ground beef, finely chopped medium onion, garlic powder, Italian seasoning, and season with salt and pepper. Mix until just combined and form into 4 patties.

Heat olive oil in a skillet over medium-high heat until shimmering. Cook the burger patties for 4-5 minutes on each side until done, forming a nice brown crust.

In the last minute of cooking, add pizza sauce, fresh basil, mozzarella cheese, and pepperoni to each patty. Cover to melt the cheese.

Assemble the burgers by placing the cooked patties on the bottom half of toasted garlic buns and topping with the other halves. Serve immediately.