This is how I like to make spinach pie. It is probably cheesier than what is traditional. I like the mozzarella because, well, who doesn't like mozzarella? Often it is made with dill, but once I tried parsley, I preferred it that way. This recipe is easy to cut in half, but the finished product also freezes pretty well. Traditionally each piece of phyllo is brushed with butter or a mixture of butter and oil, but I find this way easier and the result is good. The phyllo needs the butter or oil to properly cook and puff and get flaky.
Wash spinach well. Wilt the spinach in a large, covered Dutch oven or in a skillet in batches. The water from washing is enough so you do not need to add any more water. When cool enough, squeeze out water with your hands. If using frozen spinach, let thaw then squeeze out excess water with your hands as well.
Place spinach in a large mixing bowl, then combine with green onion, cheeses, and parsley. Season with a little black pepper. It should be salty enough with the cheeses, but you can add a little salt if you prefer. You can taste it before stirring in the eggs.
Preheat oven to 350 degrees F. Spray the bottom of a 9x13-inch baking dish with cooking spray. Working with phyllo is not really all that hard. Just be sure to keep the sheets you are not currently working with covered with plastic wrap so they do not dry out. The phyllo is very delicate, but if you go slow and gently, you should have no problem. Each sleeve comes with 15 sheets of dough. You will place them in the pan by twos, then lightly spray with the cooking spray. So, two sheets in the bottom of the dish, spray. Two more sheets, spray. Two more, spray. Spread half the spinach mixture onto the phyllo. Two sheets, spray. Two more, spray. Remaining spinach mixture spread out. Two more phyllo, spray. Use all the phyllo. With the tines of a fork, or sharp knife, cut through the phyllo in a pattern approximately where you will like to cut the spinach pieces once cooked. This will make it easier to cut the finished pie.
Bake at 350 degrees F until golden brown, about 1 hour. Let cool in the pan around 15 minutes, then cut and serve. Spanakopita is good hot or at room temperature.