In a large mixing bowl, combine the ricotta cheese, about three quarters of the mozzarella cheese, parmesan cheese, the egg, garlic powder, oregano, parsley slat, and ground pepper. Mix well until the cheese uniform.

Pre-heat oven to 375 degrees.

In a 10 '' by 13 '' oven safe dish, take about 1 cup of the tomato sauce and line the bottom and sides.

Add half of the just barely al dente-cooked orecchiette to the dish and spoon about 2 cups of the tomato sauce, half of the cheese mixture, and half of the pancetta. Stir well until the pasta is well coated. Add the remaining pasta, the remaining cheese mixture and pancetta, and another two cups of the tomato sauce. Again, mix until all of the pasta is uniformly coated. Mixing in stages just makes it easier to get uniformly coated pasta.

Now, add the spinach and very gently mix to uniformity, about 1/2 of the spinach at a time.

Top with the remaining 1 cup of tomato sauce and the remaining mozzarella cheese.

Cover with foil, place in oven and bake on lower rack, for about one half hour. Remove foil and finish baking until the mozzarella cheese is nice and bubbly, about another 15 minutes, more or less, let the cheese tell you when it is done.

Remove and spoon into separate dishes while nice and hot, topped with Pecorino-Romano cheese to taste.