Preheat your panini press or a non-stick skillet over medium heat for about 5 minutes.

Combine 1 tablespoon of softened butter, 1/4 teaspoon of garlic powder, and 1/4 teaspoon of Italian seasoning in a small bowl and whisk until smooth.

Spread the seasoned butter on one side of each slice of bread.

Flip the bread slices and spread 1/4 cup of pizza sauce evenly over the unbuttered side of both slices.

Sprinkle 4 ounces of shredded mozzarella on one of the sauced slices, followed by 16 slices of pepperoni and any optional toppings.

Close the sandwich with the other slice of bread, ensuring the buttered side is facing out.

Cook the panini in the preheated press or skillet for about 3-5 minutes per side until golden brown and cheese is melted.

Remove from heat and let cool for about a minute on a cutting board.

Slice the panini in half and serve with extra pizza sauce for dipping.