Preheat oven to 350 degree F. Place rinsed spinach in a large heavy pot with a lid. Steam it on medium high heat for about 6 minutes, stirring occasionally, until leaves are wilted. You do not need to add water, the water on the leaves is enough for steaming. Rinse and drain the spinach in a colander two times. Squeeze the spinach between your hands to get the water out. Coarsely chop.
In a large mixing bowl, combine the chopped spinach, crushed garlic, green onion, onion, matzo meal, eggs, feta cheese, rosemary, nutmeg, cinnamon, salt, and pepper. Mix well.
Lightly grease a 9x13 or 8x14 inch glass baking dish with olive oil or olive oil spray. Measure olive oil into a small bowl. Use a brush to lightly spread the oil over 2 sheets of the matzo one side only. Place, oil side up in the bottom of the dish. Spread the spinach mixture evenly over the matzo. Brush remaining 2 sheets with oil and place on top.
Bake the pie about 30 minutes, until the top is brown and crispy. Let stand for 3 minutes, and then slice into 16 pieces.