In a large mixing bowl, combine ground beef with Italian seasoning, garlic powder, and salt and black pepper to taste. Gently mix until just combined, then form into four equal burger patties, about 1/2 inch thick.

Preheat your grill or grill pan over medium-high heat for about 5 minutes. Simultaneously, turn on the broiler in your oven.

Arrange the hamburger buns cut side up on a baking sheet and place them under the broiler for about 2-3 minutes until golden brown.

Carefully place each burger patty onto the hot grill and cook for 4-5 minutes on one side. Flip and grill for an additional 4-5 minutes until they reach your desired doneness.

Heat pizza sauce in a small saucepan over low heat for about 5 minutes, stirring occasionally.

Spread warm pizza sauce on each toasted bottom bun, followed by mozzarella cheese and a few pepperoni slices. Place under the broiler for about 2-3 minutes, watching closely until cheese is melted.

Top each burger patty with more pizza sauce, mozzarella cheese, and additional pepperoni slices. Return to broiler for about 1-2 minutes until cheese is bubbly.

Add the top halves of the toasted buns back on. Let them rest for a minute before serving hot.