Preheat your waffle maker and oven. Melt the butter and brush the waffle maker generously with some of it.
Line a baking sheet with parchment paper and set aside.
In a medium bowl, whisk the eggs and sea salt until smooth.
Stir in 1½ cups of the shredded mozzarella cheese and the Italian seasoning until well combined.
Pour the batter into the waffle maker (do not fill it completely — the batter will expand and can overflow).
Cook until golden brown and crispy (about 5 minutes, depending on your waffle maker).
Transfer each finished chaffle to the parchment-lined baking sheet and keep them warm in the preheated oven while you cook the rest.
Once all the chaffles are done, top each one with the remaining mozzarella cheese, a spoonful of marinara sauce, and mini pepperoni.
Switch the oven to broil and return the topped chaffles to the oven for about 2 minutes, or until the cheese is melted and the pepperoni is sizzling.
Serve immediately and enjoy!