In a large skillet over medium-high heat, cook Italian sausage and ground beef until browned.
While the meat mixture is cooking, heat olive oil in a pot over medium heat. Add onions and garlic and saute until they start to soften and become fragrant.
Add the tomatoes, oregano, basil, thyme, red pepper flakes, salt, pepper, and sugar. Add the meat mixture. Bring to a simmer and stir occasionally. Simmer for 25 to 30 minutes. After that time, remove 3 to 4 cups of the sauce into a separate bowl to cool slightly.
Preheat oven to 375 degrees.
In a separate bowl, mix together the ricotta cheese, 2 cups of the grated mozzarella, parmesan, and egg. Mix until just combined.
In a large pot, cook the Ziti according to package directions until not quite al dente. Drain the pasta and rinse under cool water to stop the cooking. Pour it into the bowl with the cheese mixture and toss to slightly combine. Add the cooled meat sauce to the cheese and pasta and toss to combine.
Add half the coated pasta to a large casserole dish or lasagna dish. Spoon half of the remaining sauce over the top, then top with half the remaining mozzarella cheese. Repeat with another layer of the coated pasta, the sauce, and the mozzarella.
Bake for 20 minutes, or until bubbling. Remove from oven and let stand 5 minutes before serving.
Make Ahead Directions:
Allow the ziti to cool down and then refrigerate for up to 3 days or freeze for up to 3 months. Preheat the oven to 375 and bake the Ziti covered with foil for 1 to 1 1/2 hours until heated through. Remove the foil and bake for an additional 15 minutes, or until the cheese is bubbly and lightly browned.
Like I mentioned earlier, this recipe makes more Baked Ziti than will fit in a 9x13 pan. You are going to want a larger, casserole dish.Adapted from this recipe from the Pioneer Woman.
Baked Ziti from Sam's Dish http://samsdish.com/baked-ziti/