01 - Preheat oven to 400°F. Grease a 9x13-inch baking dish with cooking spray or a light coating of oil.
02 - Arrange the frozen tater tots in a single layer in the prepared dish. Drizzle evenly with olive oil. Bake for 20 minutes until lightly golden and beginning to crisp.
03 - Remove the dish from the oven. Spread the pizza sauce evenly over the partially cooked tots. Sprinkle with dried oregano, dried basil, and garlic powder.
04 - Top with half of the shredded mozzarella and cheddar cheese. Distribute pepperoni slices (if using), black olives, diced bell pepper, and red onion evenly across the surface. Sprinkle with remaining mozzarella, cheddar, and the grated Parmesan.
05 - Return the casserole to the oven and bake for an additional 20 minutes, or until the cheese is fully melted, bubbly, and golden brown on top.
06 - Allow the casserole to rest for 5 minutes before serving. This helps the cheese set slightly for easier scooping.