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 baking dish. Drizzle with 2 tablespoons olive oil and toss gently to coat. Bake for 20 minutes until lightly golden and starting to crisp.
03 - Remove dish from oven. Spread pizza sauce evenly over the partially cooked tater tots. Sprinkle dried oregano, basil, and garlic powder over the sauce.
04 - Sprinkle half of the mozzarella and cheddar cheese over the sauce. Distribute pepperoni, black olives, bell pepper, and red onion evenly across the dish. Top with remaining mozzarella, cheddar, and Parmesan cheese.
05 - Return casserole to oven and bake for 20 additional minutes, or until cheese is fully melted, bubbly, and lightly golden brown on edges.
06 - Let casserole rest for 5 minutes before serving to allow cheese to set. Cut into squares and serve warm.