Cook spaghetti al dente according to package instructions and drain (do not rinse).

Meanwhile, in a medium saucepan, over medium heat, melt the butter. As the butter cooks it will begin to foam. Skim the foam from the top with a spoon to a small bowl and discard. Cook the butter until it begins browns (do not burn). Remove from heat.

Pour the cooked pasta into a large bowl. Pour the browned butter over the pasta. Add the cheeses, toss to coat. Serve immediately garnished with fresh chopped parsley.