Cook ziti for 2 minutes less than package directions. Drain, return to pot.
Preheat oven to 180°C/350°F.
Heat 1 tbsp olive oil in a large skillet over high heat. Add 1 chopped onion and 3 minced garlic cloves; cook for 2 minutes until onion is translucent.
Add 500g ground meat; cook, breaking it up, until just browned. Stir in 1 tsp dried basil, 1 tsp dried oregano, and 1 tsp sugar and cook for 2 minutes.
Add 700g tomato passata and 1/2 cup water. Bring to a simmer, reduce heat, and cook for 10 minutes. Season with salt and pepper.
Pour about 2 cups of sauce into the pot with the ziti. Toss well.
Spread ziti mixture into a 23x33cm (9x13 inch) baking dish. Dollop with 1 cup ricotta cheese, then top with remaining sauce and 1 cup grated mozzarella cheese.
Cover dish loosely with foil. Bake for 20 minutes. Remove foil and bake for another 10-15 minutes until cheese is golden brown and bubbly.