In a medium bowl, using a rubber spatula, mix together the ricotta, mozzarella, 1/2 cup of the Parmesan, the diced pepperoni and the basil until well combined.
Butter one side of each slice of bread. Working buttered side down, spread each slice with 1 tablespoon of the marinara. Divide the cheese mixture among 6 slices of the bread, and sandwich with the remaining slices. For each sandwich, sprinkle the top piece of bread with 1 tablespoon of the remaining Parmesan. Flip, and sprinkle the other side with an additional tablespoon of Parmesan.
To make all of these sandwiches at once, heat 2 baking pans in the oven for 10 minutes. Spray the bottom of one of the pans with cooking spray, and place the buttered and Parmesan-ed sandwiches in the pan. Spray the underside of the second pan, and place it on top of the sandwiches. Bake until golden brown and crispy, and the cheese is melted, 10 minutes.
Cut each sandwich into 3 pieces. Using a few shreds of mozzarella cheese as glue, make a face using the black olive slices as eyes, the green olive slices as a nose, and the pepperoni slices as a mouth. Melt for 4 minutes in the oven to adhere.