Step 1: Cook the Pasta
Bring a large pot of heavily salted water to a boil. Add the pasta and cook according to the package instructions, but undercook it by about 2 minutes, so it is slightly firm (al dente). It will finish cooking in the oven. Before draining, reserve about 1 cup of the starchy pasta water. Drain the pasta and set it aside.

Step 2: Sauté the Chicken and Aromatics
While the pasta is cooking, heat the olive oil in a large skillet or Dutch oven over medium-high heat. Season the chicken pieces generously with salt and pepper. Add the chicken to the skillet and cook for 5-7 minutes, until it is lightly browned and cooked through. Remove the chicken from the skillet and set it aside.

Step 3: Build the Flavor Base
To the same skillet, add the chopped onion and cook for 4-5 minutes, until softened and translucent. Add the minced garlic and cook for another minute until fragrant, being careful not to burn it.

Step 4: Create the Creamy Sauce
In a blender, combine the full-fat cottage cheese and 1 cup of the marinara sauce. Blend on high speed for 1-2 minutes, or until the mixture is completely smooth and velvety. There should be no lumps remaining.

Step 5: Combine the Sauce Ingredients
Pour the blended cottage cheese mixture into the skillet with the onions and garlic. Add the remaining marinara sauce, the cooked chicken, and the Italian seasoning. Stir everything together and bring the sauce to a gentle simmer. Let it cook for 5 minutes for the flavors to meld. Taste the sauce and adjust the seasoning with more salt and pepper if needed.

Step 6: Assemble the Pasta Bake
Preheat your oven to 375°F (190°C). In a large bowl or right in the pot if it’s large enough, combine the cooked pasta with the creamy chicken and marinara sauce. Stir well until every piece of pasta is coated. If the mixture seems too thick, stir in a splash of the reserved pasta water until it reaches a nice, saucy consistency.

Step 7: Bake to Golden Perfection
Transfer the pasta mixture into a 9×13 inch baking dish and spread it into an even layer. Sprinkle the shredded mozzarella cheese and grated Parmesan cheese evenly over the top. Bake, uncovered, for 20-25 minutes, or until the sauce is bubbly and the cheese on top is melted and golden brown. For a crispier top, you can switch the oven to the broil setting for the last 1-2 minutes, but watch it very carefully to prevent burning.

Step 8: Rest and Garnish
Remove the pasta bake from the oven and let it rest for at least 10 minutes before serving. This allows the sauce to set up slightly, making it easier to serve. Garnish with fresh chopped parsley before scooping and enjoying.