01 - Preheat oven to 400°F. Grease a 9x13-inch baking dish with cooking spray or additional olive oil.
02 - Arrange the frozen tater tots in a single layer across the prepared baking dish. Drizzle olive oil evenly over the tots. 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 baked tater tots using a spatula or the back of a spoon. Sprinkle evenly with dried oregano, dried basil, and garlic powder.
04 - Sprinkle half of the mozzarella and cheddar cheese over the sauce layer. Arrange pepperoni slices, black olives, diced bell pepper, and red onion evenly across the cheese. Top with the remaining mozzarella and cheddar, then finish with 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 beginning to turn golden brown.
06 - Remove from oven and let the casserole rest for 5 minutes before serving to allow the cheese to set for easier scooping.