Preheat oven to 350°F. Line baking sheet with parchment paper.
Place pretzels on parchment paper in even layer. Top with cheddar and pepperoni. Bake for 10-15 minutes or until the cheese is melted and the pepperoni is browning. Remove and top with some grated Parmesan. It can be served at room temperature or warm.
Cut the sharp cheddar cheese where it is just larger than the pretzels so it melts over it.
User thick slice pepperoni so you get more pepperoni flavor.
Use freshly grated Parmesan to top the chicken. Never buy pre-shredded Parmesan cheese as it contains wood pulp. Blocks of Parmesan cheese are also cheaper.