Begin by boiling a large pot of salted water.

In a skillet, heat olive oil over medium heat.

Add ground beef or sausage, breaking it apart with a spoon until browned, about 7-10 minutes.

Add chopped onion and garlic to the skillet, cooking until softened.

Stir in crushed tomatoes, oregano, salt, and pepper. Let the sauce simmer for about 10 minutes.

In a bowl, combine ricotta cheese with half the mozzarella and Parmesan.

Drain the pasta and mix it into the sauce. Add the ricotta mixture and stir gently.

Transfer the mixture into a baking dish, spreading it evenly and topping with remaining mozzarella and Parmesan.

Cover with aluminum foil and bake in a preheated oven at 375°F (190°C) for 20 minutes.

Remove the foil and bake for another 10-15 minutes until bubbly and golden.