Boil ziti pasta in salted water until al dente
Drain the pasta
Cook ground beef or sausage in a skillet until browned
Add chopped onion and garlic, and cook until softened
Stir in marinara sauce
Mix the cooked pasta with the sauce
Add ricotta cheese, mozzarella, and grated Parmesan
Transfer to a baking dish
Top with more mozzarella and Parmesan
Bake at 375°F until hot and bubbly
Let rest briefly before serving