01 -
Spread marinara or pizza sauce on one side of each slice of bread.
02 -
Layer mozzarella cheese on one slice of bread, add pepperoni, and top with additional cheese if desired.
03 -
Close the sandwich with the second slice of bread, ensuring the sauce side faces inward.
04 -
Spread softened butter on the outer sides of each assembled sandwich.
05 -
Heat a skillet over medium heat and grill the sandwiches for 3-4 minutes on each side until the bread is golden and the cheese has melted.