Make meatballs:

In a bowl, stir together well turkey, garlic, bread crumbs, onion, pine nuts, parsley, egg, salt, and pepper and form into meatballs about 1-inch in diameter. In a large heavy skillet heat 2 tablespoons oil over moderately heat heat until hot but not smoking and cook half of meatballs, shaking skillet, until browned and cooked through, about 4 minutes. Transfer meatballs to paper towels to drain and brown remaining meatballs in remaining 2 tablespoons oil in same manner.

Preheat oven to 375 degrees and oil a 3 to 4 quart gratin dish or other shallow baking dish.

In a kettle of salted boiling water cook pasta until just al dente, about 8 minutes, and drain well. In a small bowl toss together mozzarella and Romano. Spoon about 1 1/2 cups tomato sauce and half of meatballs into prepared dish and spoon half of pasta on top. Spread half remaining sauce and half cheese mixture over pasta. Top with remaining meatballs and drop dollops of ricotta over meatballs. Spread remaining pasta over ricotta and top with remaining sauce and remaining cheese mixture. Bake penne in middle of oven 30 to 35 minutes, or until golden, and let stand 10 minutes before serving.