Preheat your oven to 350°F (177°C).

Bring a large pot of salted water to a boil and cook the spaghetti until al dente, about 8-10 minutes. Drain and set aside.

In the same pot, add cubed cream cheese over low heat and stir until melted and creamy, about 3-5 minutes.

Gently fold the cooked spaghetti into the pot. Add pasta sauce and undrained diced tomatoes, mixing until fully coated.

Mix half of the shredded cheese into the spaghetti mixture until combined.

Transfer the mixture to a greased 2-quart casserole dish and top with remaining shredded cheese.

Bake in the preheated oven for 30 to 35 minutes until the cheese is bubbly and golden.

Let the dish cool for about 15 minutes before serving.