Preheat your oven to 375°F (190°C). Grease a 9x13-inch baking dish with olive oil or nonstick spray and set aside.

Bring a large pot of salted water to a boil. Cook the ziti for 2 minutes less than the package directions indicate (it should be slightly undercooked). Drain and set aside.

In a large skillet or Dutch oven over medium-high heat, cook the ground beef and Italian sausage, breaking it up with a wooden spoon, until browned and cooked through, about 8–10 minutes. Drain excess fat.

Add the diced onion to the pan and cook until softened, about 4 minutes. Add the garlic and cook for 1 minute more until fragrant.

Pour in the marinara sauce and stir to combine. Add dried oregano, red pepper flakes, and the pinch of sugar. Season with salt and black pepper. Simmer over low heat for 10 minutes, stirring occasionally.

In a medium bowl, stir together the whole-milk ricotta, egg, chopped basil, salt, and pepper until smooth and well combined.

Spread about 1 cup of meat sauce on the bottom of the prepared baking dish.

Add half the cooked ziti in an even layer. Dot the ricotta mixture evenly over the pasta — you don't need to spread it perfectly, just distribute it in spoonfuls.

Sprinkle 1 cup of shredded mozzarella over the ricotta layer.

Add the remaining pasta, then pour the rest of the meat sauce evenly over the top. Sprinkle with the remaining 1 cup of mozzarella and all the Parmesan.

Cover the dish tightly with aluminum foil and bake for 20 minutes.

Remove the foil and bake for an additional 15–20 minutes, until the cheese is bubbly, golden brown, and beginning to blister at the edges.

Remove from the oven and let the baked ziti rest for 10 minutes before serving. Garnish with fresh basil and extra Parmesan if desired.