01 - Preheat oven to 400°F. Grease a 9x13-inch baking dish with cooking spray or additional olive oil.
02 - Arrange 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 dish from oven. Spread pizza sauce evenly over the partially baked tater tots. Sprinkle with dried oregano, basil, and garlic powder.
04 - Top with half of the shredded mozzarella and cheddar cheese. Arrange pepperoni, black olives, bell pepper, and red onion evenly over the cheese. Sprinkle remaining mozzarella, cheddar, and Parmesan cheese on top.
05 - Return casserole to oven and bake for an additional 20 minutes, or until cheese is fully melted, bubbly, and golden brown on top.
06 - Let casserole rest for 5 minutes before serving to allow layers to set and make serving easier.