Combine the spinach, garlic, onion powder, cream cheese, mayonnaise, sour cream, Parmesan, and some mozzarella. Season with kosher salt and ground black pepper.
A crowd-pleasing creamy Hot Spinach Dip made with three kinds of cheese, mayonnaise, sour cream, and Parmesan Cheese all baked to golden perfection and served with a variety of fresh vegetables and crackers.