Preheat the oven to 375°F (190°C).
Prepare the peppers by slicing them in half lengthwise and removing the seeds.
In a mixing bowl, combine softened cream cheese, chopped pepperoni, shredded mozzarella, garlic powder, Italian seasoning, salt, and pepper.
Fill each pepper half with the cream cheese mixture, packing it in firmly.
Place the filled peppers on a baking sheet lined with parchment paper.
Drizzle the assembled poppers with olive oil, if desired.
Bake in the preheated oven for 20-25 minutes or until the peppers are tender and the filling is bubbly.
Remove from the oven and let cool slightly before serving.