Set a small nonstick skillet over medium heat. Add the mini pepperoni to the skillet and cook, stirring occasionally, until the fat has rendered out and the edges begin to curl inwards, about 4 minutes. Remove to a paper towel-lined plate and set aside for assembly.
In a food processor, combine the cheeses, pesto, crushed red pepper and salt and process until a thick paste is formed, about 30 seconds. Add the basil and pulse just until incorporated (be careful that the mixture is not overworked or it will turn green in color).
Pour the cheese mixture into a bowl and fold in the pimentos. Scoop a heaping tablespoon into the center of each endive leaf (the larger leaves work best). Sprinkle the crispy pepperoni over the cheese mixture. Garnish each endive cup with a slice of black olive and piece of fresh parsley.