1. Combine ground beef, pepperoni, salt and pepper and gently mix.
2. Shape mixture into four patties.
3. Cook patties 5 minutes on each side over medium heat or grill over medium heat for 5-7 minutes on each side.
4. Top each burger with slice of cheese and 1/4 cup marinara sauce.
5. Serve on buns.
Tip: Over mixing ground beef makes the burger tough.