To prepare the crostini ai pepperoni with sweet pepp appetizers recipe, first you will need to prepare your arrostiti. This is the bread that is used to make the appetizer. Cut your bread in half lengthwise and cut each half into 4 pieces. Place the slices of bread on the baking sheet and brush with olive oil. Bake for about 20 minutes or until the cheese is melted. Remove the pan from the oven and sprinkle with salt and pepper to taste.