Preheat oven to 350 degrees Fahrenheit.
Cook pasta according to package instructions. Before draining, reserve 1 cup of pasta water. Drain pasta and transfer to a 9 x 13 baking dish.
In a large pot (preferably the one used for cooking pasta), melt butter over medium heat. Whisk in flour and cook for 2-3 minutes, ensuring the roux doesn't burn.
Gradually add heavy cream or half and half, whisking constantly. Then add the cream cheese and reduce heat to low.
Whisk in 8 oz of sharp cheddar cheese and 4 oz of Monterey Jack cheese until melted. Stir in cumin, salt, and black pepper to taste. Adjust seasoning if necessary. If the sauce is too thick, whisk in some of the reserved pasta water.
Once the sauce is flavorful, pour it over the noodles in the baking dish. Mix until the sauce evenly coats the noodles. Sprinkle the remaining cheese on top.
Bake on the middle rack for 25 minutes. Then switch the oven to broil and cook for an additional 2-3 minutes or until the top is golden brown.
Allow it to rest for 5 minutes before serving. Enjoy your delicious macaroni and cheese!