Boil the ziti in 2 quarts of salted water for 5 minutes until al dente. Drain the water then toss the cooked ziti in 1 tablespoon of olive oil. Set aside.
Preheat the oven to 375°F. In a large heavy-based pot, drizzle the rest of the olive oil on MED-HIGH heat. Add the sausage meat and bacon to brown for 5–8 minutes.
Add the onion, garlic, celery, and carrots into the pot. Sauté for 5–8 minutes.
Pour in the marinara sauce, Italian herbs, fresh basil, and a pinch of salt and pepper and stir. Turn down the heat and simmer for another 5 minutes then turn off the heat.
Meanwhile, whisk the eggs, ricotta, half the mozzarella, and a pinch of salt and pepper together.
Pour the cooked ziti into the pot with the meat sauce then mix together.
Pour half of the pasta and sauce into a 9" x 13" casserole dish. Spread half the egg and cheese mix all over. Layer on the rest of the pasta. Top with the rest of the egg and cheese mix and then sprinkle the other half of the mozzarella and the Parmesan.
Bake in the oven for 20–25 minutes, until the cheese is golden brown and bubbling.