Begin by bringing a large pot of salted water to a boil. Once boiling, add the spaghetti and cook according to the package instructions until al dente, about 8-10 minutes. Drain and set aside.

In the same warm pot, add cubed, softened cream cheese and stir constantly over low heat until melted and velvety.

Return the drained spaghetti to the pot and add pasta sauce and undrained diced tomatoes. Stir until well-coated.

Incorporate half of the shredded cheese into the spaghetti mixture, mixing well.

Transfer the spaghetti mixture into a greased casserole dish, spreading it out evenly.

Sprinkle the remaining shredded cheese generously over the pasta mixture.

Preheat your oven to 350°F (177°C) and bake uncovered for 30-35 minutes until bubbly and golden brown.

Let the casserole cool for about 15 minutes before serving.