In a large bowl, mix together the spinach, mozzarella, feta, ricotta, eggs, parsley, garlic powder, salt and pepper until well combined; set aside.
1 10 oz pkg frozen spinach, 1 cup shredded mozzarella cheese, ½ cup feta cheese, ½ cup ricotta cheese, 2 large eggs, 2 tablespoons minced parsley, ½ teaspoon garlic powder, ¼ teaspoon salt, ¼ teaspoon cracked pepper