Preheat your oven to 350°F and spray a 9x13 inch baking dish with cooking spray. While the oven heats, finely chop the onion, mince the garlic cloves, and measure out all your spices, sauces, and cheeses. Having everything prepped and ready will make the cooking process smooth and prevent any burning or overcooking of the meat mixture while you're scrambling to find ingredients.

While you're prepping ingredients, bring a large pot of salted water to a boil and cook the ziti according to package directions until just al dente (about 1 minute under the suggested time). Drain the pasta but do not rinse it—the starch on the surface helps the sauce cling better. Set aside in a large bowl.

Heat a large skillet over medium heat and add the chopped onion. Cook for about 5 minutes, stirring occasionally, until the onion becomes soft and translucent. Add the minced garlic and stir constantly for 1 minute until fragrant. This aromatic foundation creates the flavor base for your entire sauce—don't skip this step as it develops sweetness and depth.

Increase the heat to medium-high and add the ground beef and Italian sausage to the skillet with the aromatics. Cook for 8-10 minutes, breaking up the meat with a spoon as it cooks, until both are fully browned and no pink remains. I prefer to cook the meat thoroughly at this stage before adding liquids so it develops a deeper color and flavor through browning.

Add the marinara sauce, diced tomatoes, Italian seasoning, dried oregano, and red pepper to the browned meat mixture. Stir well to combine and bring to a gentle simmer over medium-low heat. Let this simmer for 20 minutes, stirring occasionally. This simmering time allows the flavors to meld together and the sauce to thicken slightly, creating a richer, more cohesive filling.

Remove the skillet from heat and add the softened cream cheese to the hot meat sauce. Stir constantly for 1-2 minutes until the cream cheese is completely melted and fully incorporated into the sauce. The residual heat should melt it smoothly without any lumps forming. This creates a creamy, luxurious sauce that coats the pasta beautifully.

Pour the cooked ziti into the prepared 9x13 baking dish, then spoon the meat sauce mixture from Step 6 evenly over the top, stirring gently to combine. Top with the shredded mozzarella and freshly grated Parmesan cheese, distributing them evenly. Cover the dish tightly with foil and bake for 25 minutes, then remove the foil and bake for an additional 5-10 minutes until the cheese is melted and lightly golden. I like to let the uncovered bake time go the full 10 minutes if you want the cheese slightly browned and the edges a bit crispy.