Let the butter froth, then add 100 ml cream and reduce to half. Season to taste with salt and grated nutmeg.
Cook the spaghetti al dente according to the instructions on the packet. Pour into a colander, drain and return to the saucepan. Now add the cream and butter reduction to the spaghetti, add the rest of the cream and the grated Parmesan. Mix well.
Arrange and serve sprinkled with white pepper.
Tip: Also works well with wider pasta such as linguine, tagliatelle, etc.