Begin by preparing the flavorful butter spread. In a medium-sized bowl, combine the soft butter, grated parmesan cheese, garlic powder, and dried Italian seasoning. Mix until smooth and well incorporated.
Take each slice of white bread and generously spread the butter mixture on one side of each slice. Ensure that the butter is evenly distributed.
Heat a skillet over medium-low heat. Place one slice of bread butter side down in the skillet. Layer with a slice of mozzarella cheese, followed by 6 slices of pepperoni, another slice of mozzarella cheese, 6 more pepperoni slices, and finally, another slice of mozzarella cheese.
Top the layers with another slice of bread, butter side facing up. Allow the sandwich to cook until the bottom is golden brown, which typically takes around 3-5 minutes.
Carefully flip the sandwich using a spatula and continue cooking until the other side turns golden brown, and the cheese is thoroughly melted.
Once cooked to perfection, remove the Pizza Grilled Cheese from the skillet and serve immediately. For an authentic pizza experience, pair it with warm pizza sauce for dipping.