Butter one side of each piece of bread, and coat with grated parmesan cheese.
On 4 of the unbuttered sides of bread, spread a layer of ricotta and then add a layer of tomato sauce.
Next add 4 fresh basil leaves, 10 pepperoni, and 2 mozzarella slices to each.
Heat a large frying pan to medium heat and add butter to the pan. Add 2 of the open sandwiches with the buttered side down.
Put 2 of the top slices of bread with buttered side up on top and cook for about 4 to 5 minutes. Flip and repeat until cheese is melted and bread is golden brown and remove from pan.
Add more butter and repeat again to cook the last 2 sandwiches.
Cut each sandwich in half, plate, and serve.