Add the Roma tomatoes and enough water to cover them completely to a medium saucepan over high heat. Bring to a boil and cook for 10 minutes or until softened and the skin starts to peel off.

Reserve 1 cup of the cooking water, then remove the tomatoes from the saucepan with a slotted spoon and transfer them into a bowl or plate. Allow them to cool slightly until you can handle them.

Remove the skin from the tomatoes and place them inside a blender along with the reserved cooking water, garlic, white onion, and salt. Blend until smooth and set aside.

In a large skillet, heat the olive oil over medium heat. Add the blended tomato mixture and cook for 10-15 minutes until the sauce has thickened and coats the back of a spoon.

Add the cream cheese and Mexican crema to the skillet. Whisk continuously until the cream cheese and crema are fully incorporated, about 5 minutes. Remove the skillet from the heat and set aside.

Fill a large pot or Dutch oven with water and stir in a generous amount of kosher salt. Bring to a boil, add the spaghetti, and cook until al dente, about 10 minutes or according to package directions.

Strain the pasta and add it back into the pot. Pour the reserved creamy tomato sauce and toss together until the pasta is evenly coated.

Cook for an additional 1-2 minutes to allow the sauce to incorporate into the pasta.

Serve in bowls and garnish with queso fresco.